Roush Rear Valance Kit Aero Foil Mustang GT 2018-2023

95% of 100


  • TPO Plastic Construction
  • Requires Drilling
  • Sold As A Pair
  • Made In The USA

Roush Rear Valance Aero Foil Kit for 2018, 2019, 2020, 2021, 2022, and 2023 GT Mustangs.

If you're looking to show off your 2018-2023 GT Mustang's rear quad exhaust tips, than this Roush Rear Valance Aero Foil Kit (422085) is right up your alley! Snag your kit from CJ Pony Parts today!

Features and Benefits:
- Adds an aggressive, race-inspired touch to your pony's rear valance
- Separates the airflow beneath your vehicle for improved aerodynamic efficiencies
- Constructed from injection-molded TPO with OEM-style black stipple finish
- Lightweight, impact-resistant, durable and flexible
- Designed with Ford's OEM CAD data to ensure an exact, precise fit
- Includes templates and hardware for install
- Proudly manufactured here in the U.S.A.

*This rear valance aero foil kit will NOT fit on EcoBoost or and Shelby model Mustangs.

You'll absolutely love the way this rear valance aero foil kit looks after you install it onto your brand-new GT Mustang! Roush designed this direct-fit upgrade kit from the Ford original CAD data so you know it'll be a perfect fit to your pony's rear valance. It uses techniques from professional racing to help improve the aerodynamic efficiencies of your GT--it separates the airflow underneath your vehicle, allowing a smaller portion to follow the underbody contours and adjusting the rear downforce. Each piece of this kit is crafted from superior TOP with an OEM-style black stipple finish. Install is quick and easy since everything you'll need for the project is included, even detailed directions. Be sure to order your upgraded rear valance kit from CJ's now!

Tech Tip: Minor modification to your pony's rear valance is required for mounting during installation.

California Residents: Proposition 65 Warning

Installation Difficulty


Intermediate skill is required for this installation.

Installation Videos

Video Transcript

Today, we're going to add a little bit more Roush style to our 2018 Mustang with the rear diffuser kit.

This Roush airfoil kit is going to create a custom rear diffuser on the back of your 2018-2022 Mustang GT when it's installed. They're made of a TPO plastic in your original style texture, so they'll look very factory when they're installed on the car. Installation is very straightforward. Today, we show you how but installing it on a 2018 Mustang GT.

For this installation, a lift or a jack and jack stands will make it easier. You need a quarter inch ratchet, a seven millimeter socket, eight millimeter socket, short extension, drill, quarter inch drill bit, and an eight inch drill bit.

Start by making sure your valance is completely clean. Use some soapy water, even some alcohol, if you have to. Once it's clean, you're going to grab one of the diffusers, put a piece of tape right here. What this is going to do, this here, basically lines up with that. You're going to feel for where it's going to go. You want to have this edge kind of even with that. I'm going to remove the tape and stick it on. Okay, with it held up with a double stick tape, now, grab a drill, and drill a hole out. Okay, now, grab this provided bracket, going to slide it up into place in the valance, going to line up the holes, then thread in the bolts. Then, just snug them down.

Now, grab the inside holes, line it up against the body where you want it. Drill two small pilot holes. Now, grab the self-tapping screws included with the kit, and screw them into the pilot holes. Last hole we're going to drill is going to be right here, using our pilot bit, just line it up. Install another self-tapper. Repeat the process with the other piece, and your installation is finished.

Like a lot of other parts, the Roush rear diffuser kit is pretty simple to install, but really changed the look of the back of the car, adds a nice aggressive functional look to it. Overall, installation, as you saw, is very simple. You can probably even do this on the ground if you're careful, but getting it up in the air makes it a little bit easier. Overall, it's a 15 to 20 minute installation. Be back on the road in no time.

Vehicle Fitment

This product will fit the following Mustang years:

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