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MP Concepts Quad Exhaust Rear Diffuser (15-17 GT Premium, EcoBoost Premium)

Item 398118
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Market Price $329.99 You Save 29% ($95.00)
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$234.99 (each)

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      Product Information

      Features, Description, Reviews, Q&A, Specs & Installation


      • Aggressive Race Inspired Styling
      • Durable Injection Molded ABS Material
      • Features a Stippled Grained Texture
      • Straight Forward Installation - Cutting Required
      • Backup Sensor Compatible
      • Intended for use with Aftermarket Quad Exhaust Systems
      • Designed for Premium Chassis Packages Only (Trim Levels: 200A/201A/400A/401A)
      • Fits 2015-2017 GT Premium and EcoBoost Premium Mustang Models


      Race Inspired Styling. Add an aggressive race car inspired appearance to your 2015-2017 Premium Package Mustang by installing a MP Concepts Quad Exhaust Rear Diffuser. Designed for use with aftermarket quad exhaust systems, this Diffuser nicely compliments the lines of your Premium Package equipped Mustangs rear bumper cover.

      Quality Construction. MP Concepts manufactures their Quad Exhaust Rear Diffuser from injection molded acrylonitrile butadiene styrene (ABS) plastic using the original OEM CAD data from Ford to ensure a perfect fit. ABS is an extremely strong material known for its light-weight, superior durability and impact resistance - making it perfect to withstand the hazards of daily driven vehicles. This Rear Diffuser is completed in a fine grained stippled texture for a factory look that helps to hide the appearance of rock and stone impacts.

      Straight Forward Installation. Installation of the MP Concepts Rear Diffuser is simple and straight forward. However, it will require permanent modification to the stock rear bumper cover to remove a section of the factory diffuser. Installation can be completed in about two hours. Reuses factory reflectors.

      Backup Sensor Compatible. This MP Concepts Rear Diffuser can be installed on Mustangs equipped with or without factory installed back-up sensors and will not affect sensor operation.

      Application. This MP Concepts Quad Exhaust Rear Diffuser is specifically designed to fit 2015-2017 GT and EcoBoost Mustangs equipped with the factory Premium Chassis Packages only (Trim Levels: 200A/201A/400A/401A). Intended for use with aftermarket quad exhaust systems.

      Please Read. If you are having trouble determining what style bumper your Mustang is equipped with please refer to the comparison image above.

      MP Concepts

      Fitment: 2015 2016 2017

      MP Concepts 398118

      CA Residents: WARNING: Cancer and Reproductive Harm -


      Customer Reviews (12)

      Write a Review

      Ratings Summary

      3.8 out of 5 overall rating from 12 customers

      Installation Time: Less than 1 Hour

      • February 28, 2020

        5 2016 GT - KyleS


        Fits great with roush axelback quad tipped active exhaust

        Helpful (5)
      • August 08, 2019

        4 2015 GT - asdf7699 Installation Time: Less than 1 Hour

        Works great

        I had a small fitment issue but some Jb weld to get two of the pieces to stay together and it works great

        Helpful (6)
      • July 27, 2019

        2 2017 GT - TxMike2013 Installation Time: Afternoon

        Poor fitment. Must be modified.

        It went on the bumper with no issues. It was pretty straight forward. The directions are on colored paper but weren’t very clear. I posted two photos of the issue I had though. The mounting plate (plastic) when putting the bumper on the car is turned 90 degrees the wrong direction. I had to take a torch and heat it up so I could bend it. I used vice grips to hold it in place while I heated it up and gradually tightened them until it was in the proper place. Once this was done the winglet connectors on the side aren’t lined up correctly I will have to use an apoxy of some sort to hold them in place. Over all it looks good on the car and I like it better than the Roush option but just know it takes some modifying.

        Helpful (4)
      • May 13, 2019

        4 2016 GT - AlexQ

        Super cool look

        Look is awesome no denying but the hard ware that is supposed to transfer from OEM to mp concept valence doesn't fit and I used different hardware.

        Helpful (8)
      • April 26, 2019

        3 2016 GT - AustinK Installation Time: Less than 1 Hour

        Not bad, but not great.

        I’d give this piece a 3/5. For the most part it looks good, but the seams on the sides are absolutely awful the snap on pieces don’t snap on very well and the edges are rough. The rest of it looks nice, though. The 18 quad tipped axle backs should line right up with it.

        Helpful (3)
      • April 15, 2019

        3 2016 GT - Miknschwizz Installation Time: Afternoon

        Not a great fit

        Overall its pretty easy to take off the old diffuser, cut off the rest of the plastic. The reverse light is held in place by the factory hardware and some spacers. They do not actually thread into the valence itself. Doesnt leave me confident in feeling that it is secure. Wouldn’t recommend this based off of fitment. The side extension tab on one side was already broken off as well as niether side “snapping into place easily.” The tabs bend easy and dont want to snap in. The end fitment looks alright but just knownwhat youre getting into.

        Helpful (4)
      • February 23, 2019

        5 2015 GT - Romario Installation Time: Less than 1 Hour

        Looks very nice

        Makes a big difference and looks OEM too. I love it.

        Helpful (6)
      • February 09, 2019

        4 2017 GT - Vanessa Installation Time: Afternoon

        Solid Product BUT Patience Required

        This rear diffuser is NOT EASY TO INSTALL. Some steps in the instructions are not as clear or as easy to complete as they seem. The bumper does NOT need to come off but I recommend putting your car on jack stands to prop up the rear so you can work underneath. The ends come separated from the main piece of the diffuser which creates a minor gap in the back corners. You will also have to cut off part of the stock diffuser and reconnect the reverse light. It looks great it's finally finished.

        Helpful (8)
      • January 22, 2019

        5 2016 GT - Alejandro Installation Time: Less than 1 Hour

        Great product

        Looks pretty awesome just lne side was hard to fit in.

        Helpful (7)
      • November 14, 2018

        5 2016 GT - MikeV23

        Great fit

        Looks great, easy install and you keep the OEM reverse parking sensors in place. Thanks MP Concepts!

        Helpful (14)

      Questions & Answers (17 answers)

      5 Top Rated Questions

      Would this diffuser work with the Corsa Quad Tips? Also, could we have more product pictures with a view on the exterior of the diffuser (as if we were looking at it while it was attached to the s550s bumper. Can't really tell what it will look like when attached to a stang with the stock pictures provided, seeing as they're shots of the interior of the diffuser)

      • This is indeed intended for use with Aftermarket Quad Exhaust Systems. We are constantly looking at expanding our productpictures and will submit this request for additional pictures. 

      Helpful (5)

      Would this work with the AWE touring edition catback with quad tips?

      • Yes, this diffuser will work with that exhaust.

      Helpful (1)

      What’s the largest quad tips you can run on this?

      • We have only tested this with everything we offer on the site, so if you are buying from our site you have nothing to worry about. Alternatively, I would suggest measuring if you are going any larger than anything we offer.

      Helpful (1)

      will this work with corsa extreme

      • Yes, this should work just fine with that, as it is designed to work with Quad Tipped exhausts.

      Helpful (1)

      Will I have to remove the entire bumper like I would in the roush? Also will this fit the stock premium valance or will I have to get a quad valance?

      • The rear bumper will not need to be removed in order to install this diffuser.

      Helpful (1)
      Post Your Question
      10 More Questions
      Will it fit a ‘16 GT non-premium bumper? 0 answer
      Can this fit on my 16 Ford Mustang with the 2018 mbrp muffler delete ? 1 answer
      I have a 2015 50th Anniversary Appearance Pack, I do not have the back up sensors will this product still fit? 1 answer
      Will I still be able to use my MMD rear custom fit splash guards with this diffuser? Thanks. 1 answer
      would this work with the oem 2018 mufflers and exhaust tips? 1 answer
      Has anyone bought the diffuser and installed the Corsa quad tips with no problem? 0 answer
      Hello, it's hard to tell from the pictures but is this a one piece diffuser? Meaning is the diffuser a continuous piece from side to side? Or is it a 3 piece like the roush one? Thank you. 1 answer
      Some seems to have problem fiting this diffuser with the 4 tipped Corsa. Could you confirm that this diffuser will work with the 4 tipped Corsa touring axleback and the tips would be centered in the opening, without modifing the exhaust? 1 answer
      Would this diffuser allow me to use an '18 GT quad tip exhaust on my '17 GT? Preferably the Borla S-Type quad tip. 1 answer
      Would this product work with the Ford Performance extreme quad tip cat back part # M-5200-M8EBA? 1 answer

      Installation & What's in the Box

      Installation Info

      What's in the Box

      • (1) Diffuser - Center Section
      • (1) Diffuser - Left Side
      • (1) Diffuser - Right Side
      • (4) Spacers