2015-2021 Subaru WRX/STI V3 Diffuser

$279.99 ~~$559.98~~ In stock

Category: Subaru

Designed for the 2015–2021 Subaru WRX / STI

🔧 Direct Fitment
Specifically engineered to mount directly to the factory rear bumper with no cutting or trimming required.

🛠️ Material
Crafted from aerospace-grade lightweight aluminum for superior durability and strength.

⚙️ Finish & Build Quality
Precision CNC-cut and professionally powder coated in gloss black. Pre-drilled for straightforward installation.

Made in USA
Proudly manufactured in the United States using high-grade materials and expert craftsmanship.

Production Lead Time
CNC items are made to order and have raw materials allocated to production once the order is placed. For concerns regarding current lead times, please review the CNC Products section in our Terms & Conditions.

🧰 Install-Friendly
Includes all required hardware.
Professional installation is highly recommended.

💨 Why Add a Rear Diffuser to Your WRX/STI?
This rear diffuser enhances the WRX/STI’s aggressive styling while improving aerodynamic performance. By optimizing underbody airflow, it helps reduce drag and increase rear-end stability at higher speeds.

Customer Reviews (4.8 / 5 · 5 reviews)

Emma A. ★★★★★ Sep 12, 2026

The fitment on my 2019 STI was spot on, no trimming or drilling needed at all. The material feels rigid and well finished, and it totally changed the look of the rear end.

Lucy L. ★★★★★ Sep 11, 2026

Bolted straight onto the factory bumper holes with zero cutting, which sold me on it immediately. The fitment lines up tight against the rear bumper and the aerospa material feels stiffer than the stock plastic piece. Cleans up the back end nicely at speed.

Edward O. ★★★★★ Sep 10, 2026

I was dreading having to trim the bumper, but this bolted straight to the factory mounting points with zero cutting. The fitment is spot on for my 2019 STI and it tightened up the rear end look immediately.