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MMD Rear Diffuser (15-17 GT, EcoBoost, V6 w/Non-Premium Rear Bumper)

Market Price $249.99 You Save 20% ($50.00)
Our Price

$199.99 (each)

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  • Item 390517
  • MPN# 390517

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Features, Video & Details

  • Aggressive Fin Rear Diffuser
  • Thermoformed ABS Plastic
  • Matte Black Painted Finish
  • Minimal Drilling Required
  • Fits 2015-2017 GT, EcoBoost & V6 Mustangs
  • Designed for Base (Non-Premium) Chassis Packages Only (Trim Levels: 050A/051A/100A/300A)

Review & Installation Video

Review & Install Video

Hey, what's going on, guys? Adam here with AmericanMuscle.com. Today I'm bringing you a quick overview of the MMD Rear Diffuser fitting all 2015 and newer GT and Ecoboost Mustangs with a non-premium rear bumper. The MMD Rear Diffuser is gonna be for the 2015 and newer GT and Ecoboost Mustang owner out there looking to improve the appearance of their non-premium rear bumper, to give it the flair and style that the premium package S550s offer, without breaking the bank. It has definitely been a popular complaint between the S550 shoppers out there who picked up the GT and Ecoboost non-premium packages, that the rear balance was kind of left plain and simple from Ford. Now, this doesn't offer the exact styling and flair that the premium packages do, which is where MMD steps up to the plate to take care of that, to give you that noticeable appearance the premium packages offer. Just to give you a quick rundown if you're not aware, MMD, or Modern Muscle Design, is really one of the industry leaders when it comes to exterior styling parts for the S197s and the S550s. Now, they offer a wide variety of top of the line, high-quality parts to really change the look of your S550, like the one I have here. This option for the non-premium rear bumpers will offer the same detailed fin styling you would expect from the premium packages, offered in a matte black finish with the fins protruding out much farther than stock. Now, for the materials, you can expect a durable thermoformed ABS plastic. Now, in all honesty, this does feel a little bit thin and flimsy in your hands, but once attached to your vehicle, it will stand the test of time and be durable enough to handle whatever is thrown at it. This is finished in a matte black pre-painted color option. It is not offered in a pre-painted option to fit your factory color, but you could definitely take this to a custom shop of your own to get matched for your factory paint if you want it to blend in a little more. So one thing I do want to point out here, guys, is this will require you to make very, very minimal amount of drilling into your rear bumper. Now, the drilling will not be visible in any way, shape, or form if you do decide to remove this in the future, and it won't affect any future styling options. Now, you will be drilling into these two pre-drilled holes in the rear diffuser into the bottom of your rear bumper, but again, if this is not something you're looking to do to your rear bumper, this option may not be for you. Now, with the holes you'll be drilling, you will be putting push pins into place, just to keep it held up there. But in addition to that, to give it some added security, there is also pre-applied 3M automotive bonding tape already put onto the back of the rear diffuser, just to give it some added security and to make sure it stays in place once it's on, until you're ready to take it off. Now, the 3M tape will not at all affect your factory rear paint, if you do decide to take it off in the future. Now, for the guys out there who are still interested, expect to be spending about $250 for the MMD Rear Diffuser, which, honestly, in the grand scheme of things isn't too terrible, considering the alternative is a full rear bumper swap to the premium package just to get that premium effect, Now, this will save you all from taking too bad of a beating, while giving you some bang for your buck with that same premium package styling you are looking for. So, moving on to the installation portion, as I mentioned before, this will require a little bit of drilling, so you will want to have a drill and a proper bit on hand, as well as the pushpins, alcohol wipes and adhesion promoter that is all included in the kit. So, first things first, you wanna take your alcohol wipes provided in your kit and completely clean the factory rear valance, freeing it of all dirt and dust to make sure the 3M tape can get a good bonding. Once the area is completely clean, you can apply the adhesive promoter. Now, with the 3M tape backing still on the back of the MMD Rear Diffuser, you want to put it into place and mark the center of the pre-drilled holes on the tabs on each side, just to mark your drilling locations. From here, you wanna drill a 23/64th-inch hole through the pre-drilled holes on the tabs into your rear bumper and put into place your pushpins provided in the kit. It may be easier to do so if you jack up the car, just to comfortably have enough space to do some drilling. Once the holes are drilled and everything is in place, you can peel back the backing on the 3M tape and firmly press it into place, making sure it's lined up properly. Overall, this'll take you about a half-hour to an hour at the absolute maximum. I would definitely give this one a two out of three wrenches on the difficulty meter, simply because it does require a little bit more work with the drilling. Just to quickly wrap things up, guys, if you're the owner of a 2015 or newer GT or Ecoboost Mustang and you're looking for a way to spice up your non-premium rear bumper to give it that premium styling without breaking the bank on a complete bumper swap, you might wanna check out the MMD Rear Diffuser, which of course is available right here at AmericanMuscle.com.

Aggressive Fin Detailing. If you purchased a base model S550 Mustang, but wish you could add the same aggressive fin detailing the Premium Package models can, your wishes have been answered. MMD has created a Rear Diffuser specifically designed for 2015-2017 Mustangs equipped with the Non-Premium Rear Bumpers. Featuring a smooth matte black painted finish, this modification requires very minimal drilling and will provide a drastic visual overhaul to your Pony. With fins protruding much farther from the bumper than stock, this MMD Rear Diffuser is a must have appearance upgrade.

Quality Construction. Crafted from durable thermoformed ABS plastic, this Rear Diffuser by MMD is finished in a smooth painted matte black to blend in perfectly with the rest of your factory paneling. While you can certainly paint this diffuser for an added touch of customization, it looks menacing and aggressive as it comes. With the drilling of two small holes, you can install this new Rear Diffuser easily with the included clips and 3M tape.

Application. This MMD Rear Diffuser is specifically designed for use on 2015-2017 GT, EcoBoost and V6 Mustangs equipped with the factory Base (Non-Premium) Chassis Packages only (Trim Levels: 050A/051A/100A/300A).

Fitment: 2015 2016 2017 Details

What's in the Box
  • (1) Rear Diffuser
  • (2) Clips
  • 3M Tape
Installation Info
Will it fit my Mustang?
  • EcoBoost - 15, 16, 17
  • GT - 15, 16, 17
  • V6 - 15, 16, 17

Fits Base (Non-Premium) Chassis Packages Only (Trim Levels: 050A/051A/100A/300A)

People Who Bought This Item Also Bought

Most Helpful Reviews

1/5
Does not fit properly - Returned

Cheap quality plastic, looks good but does not fit properly without creating the huge air gap in the back end of the diffuser. The back end does not meet the edge of the bumper underneath the vehicle and ...

Read More
Helpful (4)

5/5
Nice looks!

This mod gave my mustang a well needed aggressive look.

Helpful (2)

Overall Rating 3.9 out of 5 stars
Read All 85 Reviews

Customer Photos (51) Submit Your Photo

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11 Questions / 5 Answers

Ask a Question

Does this fit a 2015 V6 convertible?

Ponyboy

  • The MMD Rear Diffuser will fit a 2015 convertible, as long as it is not a V6 premium.

    Rob D

Helpful (0)

Will MMD make a filler piece for the 1 inch gap between this diffuser and the stock bumper ? the air trapped in this space is causing this to tear off, if that gap was closed off this will be a better product at higher speeds.

Gus

How do you get a diffuser to install to a non premium number?

MattK

  • For directions on how to install the MMD Rear Diffuser you can consult our installation guides below: https://lib.americanmuscle.com/files/390517-manu.pdf

    VincentV

Helpful (0)

I truly like the way this piece looks however after so many issues being reported I am very hesitant to go forward with this option over a different route. Can this piece be modified to accept more pushpins for added security. In other words can I drill holes in the edges to add more pins? Or is the piece made in such a way that doing so would warp it or change it's intended shape?

Blake

  • While it is possible to add push pins to this for added security, it is not recommended, as modifying the product like you stated may cause warpage and bad fitment in other areas of the car.

    AMjordan

Helpful (0)

What were the tweaks made on this item? I saw the comment on youtube that is was taken off due to tweaks that were made

newstang

  • The MMD Rear Diffuser received several minor adjustments to allow better fitment and a more factory look.

    Rob D

Helpful (0)

Hello. May I know exactly the size of the box so I can see whether my friend can help me bring the item here in Doha, Qatar. I need the exact dimensions of the box/packaging. Thanks.

albert2mi

  • The box dimensions will be about 47.5" in length, 13 1/4" in width and 6 3/4" in height.

    Ricky36

Helpful (0)

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Customer Reviews (85) Write a Review

Overall Rating 3.9

out of 5 stars

Installation Time:Less than 1 Hour

Installation Cost:0-$100

  • Fit 4.1875 4.2
  • Appearance 4.671875 4.7
  • Bang For Your Buck 3.828125 3.8



  • 1/5

    Installation Time: Less than 1 Hour

    June 27, 2017

    Does not fit properly - Returned

    Cheap quality plastic, looks good but does not fit properly without creating the huge air gap in the back end of the diffuser. The back end does not meet the edge of the bumper underneath the vehicle and creates a huge gap leading to a air parachute effect. MMD could have easily molded it to sit flush with the OEM bumpers lower edge by using the 4 pre-existing OEM Push Pins to secure the diffuser.

    Sal

    Year: 2015 Submodel: V6

    Helpful (4)

  • 1/5

    Installation Time: Less than 1 Hour

    July 13, 2017

    Poorly designed product

    Easy to install but made of very flimsy cheap plastic. Mounting tape separating from bumper after one week. Would not recommend.

    Joe

    Year: 2017 Submodel: GT

    Helpful (2)

  • 5/5

    Installation Time: Less than 1 Hour

    February 28, 2017

    Nice looks!

    This mod gave my mustang a well needed aggressive look.

    JJ

    Year: 2015 Submodel: V6

    Helpful (2)

  • 1/5

    Installation Time: Less than 1 Hour

    December 01, 2016

    it can't go fast..

    if you wanna put your car on track then don't buy it... it will broke if you drive fast..

    xian

    Year: 2015 Submodel: V6

    Helpful (2)

  • 4/5

    September 20, 2016

    rear diffuser

    the diffuser fit very well. looks great. made of thin plastic. not very sturdy. for the price. see how long it last.

    chevys10

    Year: 2016 Submodel: V6

    Helpful (2)

  • 1/5

    September 02, 2016

    *Warning* Do not buy.

    This is not durable in anyway. This "Diffuser" fell apart after three weeks. This diffuser is not strong enough to hold up overtime. Angry and disappointing at MMD. I want my money back!!

    Warning

    Year: 2016 Submodel: Ecoboost

    Helpful (2)

  • 2/5

    July 29, 2016

    Looks great but plastic is cheap.

    The product looks great but the materials it's made of feels flimsy. Also there is a gap towards the front at the edge of the original diffuser towards the front of the bumper that I'm sure catches air going down the highway and have seem some on the forums where the diffuser has ripped from this. Overall the product looks great but between the material quality and the likelyhood that it's going to break I give it a 2

    Spikeyh

    Year: 2015 Submodel: GT

    Helpful (2)

  • 5/5

    July 28, 2016

    Easy install, nice ground effect!

    Wanted to carry the theme of the splitter design to the rear of the car. This was the perfect way to go. Gives the car an aggressive yet subtle appearance. Luckily l work at an Audi dealership so having access to a lift was a major advantage. All MMD needs to do now is design the rear side splitters that go between the wheel arch and rear bumper. Should take about 1/2 hour start to finish.

    Bru7

    Year: 2015 Submodel: Ecoboost

    Helpful (2)

  • 3/5

    July 25, 2016

    LOOKS GOOD - COULD BE BETTER

    I really like the look of this diffuser on the base bumper and really it is the only option other than replacement with a premium bumper. Installation was really easy and only took about 20 minutes. It gives an aggressive look to the bumper that the non-premium models really lack. There are some issues though. First of all, it feels flimsy. Maybe that will not be a problem, but it doesn't feel like it will hold up. The tape is not great. It uses a grey tape that seems to melt with high temps. You can also see it, and it doesn't look great. I think I will be replacing mine with some 3M black tape soon. The last and most concerning issue is that the front part of the diffuser (the part facing the front of the car located under the bumper) grabs a lot of air creating a parachute. This will more than likely damage the plastic over time. I put some foam between the stock bumper and the diffuser to fill the gap. I feel the price is a bit high for a thin piece of plastic that may or may not hold up. Yes it does look good, but MMD needs to beef it up a little, use a better tape, and figure out some way to connect the front to avoid damage from air flow.

    CDM77

    Year: 2015 Submodel: GT

    Helpful (2)

  • 5/5

    July 20, 2016

    Polarizing

    So this diffuser is definitely not everyones cup of tea. I love it. It looks slick and gives a mean stare to following drivers. Some people say its flimsy, cheap, and a bad attempt to "catch up" to a premium look. For me it's about the added aggression, rather than convincing someone my base model is a premium. It has some elements of a premium diffuser, and some similarities to the RTR. Overall, IMO, its an upgrade - but only if you are ok with it being a stick on and having it stick out from the bumper about 1in. Bottom line: if you want to add some flare/aggression to the blandness of your monocolored bumper, pull the trigger.

    Tarheel

    Year: 2015 Submodel: Ecoboost

    Helpful (2)

  • 1/5

    Installation Time: Less than 1 Hour

    June 27, 2017

    broke off my car lol

    It looks great appearance wise, but it feels cheap. I pulled out of my drive way one day and it was scraping on the ground as I pulled out. Hadn't been on the car for even 6 months.

    OE

    Year: 2016 Submodel: V6

    Helpful (1)

  • 1/5

    April 06, 2017

    diffuser fell apart after 2 months

    This product literally fell apart and it begain flapping against my rear bumber. I want my money back!

    JV

    Year: 2017 Submodel: GT

    Helpful (1)

  • 5/5

    Installation Time: Less than 1 Hour

    February 19, 2017

    MUST have for base Mustangs

    Great product, makes the back end look a lot more aggressive. Highly recommended!

    StingerTheStang

    Year: 2015 Submodel: EcoBoost

    Helpful (1)

  • 5/5

    Installation Time: Less than 1 Hour

    February 15, 2017

    Love it

    Definitely change the way the car looks on the back

    BradleyA

    Year: 2016 Submodel: EcoBoost

    Helpful (1)

  • 4/5

    Installation Time: Less than 1 Hour

    February 10, 2017

    Nice product

    I was hesitant to order after seeing some people having tithe diffuser comeback apart but I have been happy so far. I have not experienced any issues so far. The part was easy to install and definitely changes the look of the rear bumper.

    bfost1214

    Year: 2017 Submodel: GT

    Helpful (1)

  • 5/5

    August 29, 2016

    Looks great

    I love how the diffuser looks on my bumper I decided to buy and use the same 3m to keep it in place and I like the look for me the red 3m tape makes the black diffuser stand out .so instead of drilling holes I decided to run the 3m tape on the outside of the diffuser from one end to the other securing the 3m tape that comes with the diffuser from the outside. The ends of the diffuser were then wrapped and secured with separate 3 m tape in place of drilling.

    Jj

    Year: 2016 Submodel: GT

    Helpful (1)

  • 4/5

    August 07, 2016

    MMD Rear Diffuser

    The MMD Rear Diffuser looks good, installed fairly easy. I actually like the look better than the premium pack Ford rear diffuser. One detail I would change is the foam mounting tape would be nearly invisible if it were black instead of gray in color. You can see a small gray foam tape line where the diffuser meets the stock bumper cover. Not a big deal but a detail which could be improved. Otherwise happy with the piece.

    Coyotefan

    Year: 2016 Submodel: GT

    Helpful (1)

  • 5/5

    August 04, 2016

    Money well spent

    When I bought my Mustang GT I honestly didn't think much of the non-premium bumper. After some time, it started to bother me how bland it looked. At the time, my only option was to literally do a whole bumper swap, have it painted, and also get the rear valance, which cost quite a bit. I was hoping for some company to release something for everybody who had a non-premium bumper, and MMD came through for me again. Honestly the price is a bit high but in the end it gave me the flare and aggressive look I was ultimately looking for. This is definitely money well spent!

    MykeS

    Year: 2015 Submodel: GT

    Helpful (1)

  • 4/5

    July 28, 2016

    Great looks overall! Material ? not so sure!

    This diffuser does change the look of your non-premium bumper and for that I am very satisfied, but they could have done a little better with the material selected specially with the price range.

    BlackRose123

    Year: 2015 Submodel: V6

    Helpful (1)

  • 3/5

    July 27, 2016

    Looks good from 20 feet

    Overall this is a great piece to add to the base bumper. It is made of thin plastic to fit as flush to the bumper as possible. Once it is on it feels very sturdy and OEM like in fit. Unfortunately the front edge is secured with gray 3m mounding tape. When looking at the vehicle from behind the area around the back up light shows the tape line. The tape also gets wind and rain from behind as the diffuser and the bumper have almost 3 inches of open space at the back edge of the diffuser. This space allows water and air to be forced out small gaps in the tape bond and constantly creates new ones.

    N8beez

    Year: 2016 Submodel: GT

    Helpful (1)

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