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Defenderworx Quarter Window Louvers; Matte Black (15-21 Fastback)

Item 394120
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      Video Review & Installation

      Hey guys, today we're gonna be taking a look at and installing the Defenderworx quarter window louvers, for all 2015 to 2018 Mustangs. These are an unpainted polyurethane quarter window louver with a matte black finish. They cost about $200 and you can see they have a very stepped louvered design. They give you a little bit of a different look than some of the other options on the website. Like any other exterior mod, these are all about personal styling. You can install them right out of the box with the matte black finish or they're also very easily paintable, so you guys can paint them if you want to. They're easy to install, I'll call it a one out of three wrenches in the difficulty meter and I'll show you how we got them on the car now. All right guys, so the first step of our install is actually gonna be to flip the louver over. We're gonna apply some adhesive promoter to the flat edge all the way around the louver here and then we're going to apply the 3M tape. So I have a pair of scissors here so I can cut the tape when I need to. We're gonna go ahead right now and get the promoter on the louver before we apply the 3M tape. So we're just gonna apply the 3M tape on the flat surface of the louver here. We're gonna leave the backing on it for now. All right so we do wanna make sure that none of this 3M tape hangs over the edge of the louver because you will be able to see it. All right, I'm just gonna fill in this space right here with a smaller piece of tape just because I do wanna make sure I get as much 3M on here as possible. So with the 3M on the back of the louver, we're actually gonna flip it over now. And once again these are very lightweight and they do come with this matte black finish. They're very easily paintable, so you guys can paint match these if you want to or you can install them right out of the box with a matte black finish like we're gonna do today. So you do get two stickers from the Defenderworx. They're right here and I will say that if you're gonna paint match yours and you wanna put the stickers on, make sure you do it after they're painted. We're gonna go ahead and just stick one of these stickers up in the corner right now before we get this on the car. So at this point we're actually gonna test fit the louver before we peel the backing off the 3M tape just so we're really familiar with where it's gonna go and how it's gonna sit on the window before we go to actually install it. Another thing to say here is that you're gonna wanna make sure your window is as clean as possible. So you're gonna want to use an alcohol prep pad or anything that'll cut through any grease or wax that could be on the window. We've already gone ahead and cleaned our window. One other thing to point out is this is a louver design, so you guys can see that you will be able to see or have some light come through this louver on the new rear quarter window here. If you guys don't wanna see the unfinished backing of your louver or you don't want that light coming through, make sure you pick up a quarter panel blackout decal and install that prior to installing your louver. So we're gonna go ahead, test fit this on the car and just get a really good idea where it's gonna be. So before we go ahead and get the louver installed, we're gonna use 3M adhesion promoter on the window as well. We're only gonna be putting it where the 3M tape is gonna sit. We're gonna go ahead, just make a line around our window. Now we're gonna peel the backing off the 3M tape. Now we'll just press this into place. Gonna want to make sure that you are perfectly lined up because with the adhesion promoter on the glass the 3M tape's gonna stick right away. So now I'm just gonna go around the entire louver and make sure it's pushed into place. One of the nice things about these louvers is they apply to the glass so they're gonna leave your quarter window trim exposed. All right guys, that's gonna wrap up this review and install. Keep in mind you can always check these out more online right here at

      Product Information

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


      • Aggressive Styling
      • Louvered Design
      • Polyurethane Construction
      • Matte Black Finish
      • Simple Peel and Stick Installation
      • Driver and Passenger Side Louvers Included
      • 4-Year Limited Warranty
      • Fits all 2015-2021 Ford Mustang Fastback Models


      Aggressive Modern Design. Make your Mustang stand out at your next car show with a set of Defenderworx Quarter Window Louvers. These stepped Louvers were designed to give your fastback S550 Mustang a more aggressive muscle car appearance. With these Quarter Window Louvers on your Pony, you are guaranteed to turn heads wherever you go.

      Polyurethane Construction. DefenderWorx manufactures their quarter window louvers from industrial-grade, OEM quality injected molded polyurethane for superior strength and long lasting durability. These Louvers are completed in a matte black finish that allows them to be installed straight out of the box.

      Easy Installation. No fuss, no muss installation. DefenderWorx Quarter Window Louvers are designed to attach to the factory C-Pillar glass with the supplied 3M doubled sided automotive bonding tape for a quick and easy installation. Just clean the surface, peel the backing and stick in place - it's that easy.

      Recommended Styling Upgrade. When installing exterior quarter window louvers or scoops on your Mustang it is recommended to add a set of quarter window blackout decals to hide the ugly back side that wasn't meant to be seen by human eyes. See option above.

      4-Year Warranty. DefenderWorx guarantees to the original purchaser of its products a 4-year, 36,000 mile warranty, against manufacturer defects in materials and workmanship under normal use. Some exclusions may apply, please see manufacturer's warranty for details.

      Application. Defenderworx Quarter Window Louvers are designed to fit all 2015 to 2021 Fastback Mustangs, including the V6, EcoBoost, GT, GT350 and GT500 models. Sold as a set of two, one driver side and one passenger side.



      Defenderworx 901448

      CA Residents: WARNING: Cancer and Reproductive Harm -

      Installation & What's in the Box

      Installation Info

      What's in the Box

      • (1) Pair Quarter Window Louvers

      Tech Specs


      Customer Reviews (21)

        Questions & Answers

        10 More Questions

        Will It Fit My Mustang

        • Bullitt - 19, 20
        • EcoBoost - 15, 16, 17, 18, 19, 20, 21
        • GT - 15, 16, 17, 18, 19, 20, 21
        • GT350 - 15, 16, 17, 18, 19, 20
        • GT350R - 15, 16, 17, 18, 19, 20
        • GT500 - 20, 21
        • Mach 1 - 21
        • V6 - 15, 16, 17

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