Transform the rear aerodynamics of your 2005–2009 Ford Mustang S197 with the APR Performance GTR Carbon Fiber Rear Diffuser. Designed as a functional aerodynamic upgrade, this rear diffuser helps manage high-speed airflow traveling underneath the vehicle while adding an aggressive, race-inspired appearance to the rear of your Mustang.
As air travels underneath the vehicle, it must transition into the low-pressure wake created behind the car. The APR Performance Rear Diffuser helps control and smooth this transition, promoting more efficient underbody airflow and helping other aerodynamic components, such as a rear wing, perform more effectively.
Manufactured using autoclave-cured pre-preg carbon fiber, the APR GTR Rear Diffuser combines lightweight construction with excellent strength and rigidity for a functional upgrade suitable for both performance street builds and track-focused Mustangs.
Important Fitment Notes
Fits 2005–2009 Ford Mustang S197 models.
IMPORTANT: You must select the correct rear bumper configuration when ordering:
Standard Rear Bumper
Widebody Rear Bumper
Please verify your rear bumper configuration before placing your order.
Key Features
Functional Rear Aerodynamics Designed to manage high-speed airflow exiting underneath the vehicle and promote a smoother transition into the low-pressure area behind the car.
Improved Underbody Airflow Helps reduce turbulent airflow beneath the rear of the vehicle for improved aerodynamic efficiency.
Complements Rear Wing Setups Works in conjunction with other aerodynamic components, including APR Performance rear wings, as part of a more complete aero package.
Autoclave-Cured Pre-Preg Carbon Fiber Formed at high temperatures using pre-preg carbon fiber manufacturing processes for excellent strength, rigidity, and lightweight performance.
UV-Resistant Coating Finished with a UV-resistant coating to help protect the carbon fiber against fading and environmental exposure.
Standard & Widebody Options Available for both standard and widebody rear bumper configurations.
Vehicle Fitment
2005–2009 Ford Mustang S197
Standard Rear Bumper – select appropriate option
Widebody Rear Bumper – select appropriate option
Why Choose APR Performance?
APR Performance develops functional aerodynamic components designed to improve airflow management rather than simply provide a cosmetic upgrade. The GTR Carbon Fiber Rear Diffuser helps manage airflow exiting beneath the S197 Mustang while complementing other APR aerodynamic upgrades for a more complete performance-oriented setup.
Perfect for Mustang owners looking for:
✔ Improved underbody airflow ✔ Functional rear aerodynamics ✔ Better integration with rear wing setups ✔ Lightweight pre-preg carbon fiber construction ✔ UV-resistant finish ✔ Standard and widebody fitment options ✔ Aggressive race-inspired styling
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Customer Reviews
Overall rating: 4.8 / 5 from 5060 reviews.
I have added a ton of pieces on the interior, from the console, waterfall, speakers, door, overhead, garage buttons and the steering wheel which I highly recommend. My car is six years old and the oyster gray isn't holding up or able to clean up, so these pieces really dressed up my interior to the next level or two! Thank uou Carbonaddons!!!!
Fast service. High quality. Easy installation. Followed reviews and recommendations to test fit and heat the adhesive first. Next plan is for a splitter and door side skirts!
The first photo is the before, the second is the passenger side that looks great. Where I am disappointed in is the drivers side, if you look at the top it does not cover the original completely at the top and some of the silver shows thru. A fraction more carbon material and it would be great. That is disappointing and why I only rated it as 3 stars.
Swapping the buttons and wiring over from the stock steering wheel takes some patience, but the finished look is absolutely worth it. This F1-style wheel from Carbon addons gets A LOT of attention at car shows and really stands out in my C8. Haven’t seen anyone else with one… YET! 🤞
Ordering from Carbon Addons has been a thrill ride for my cars. You guys rock!! Keep up the hard work and dedication to your customers. Oh and your car air freshener is awesome! Love the manly smell.
We offer free shipping on CarbonAddons® products for continental U.S. orders over $199.
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1 Year Warranty
We offer a limited 1 year warranty on defects on all our products.