Give your 2020–2021 Audi A4 or S4 a bold, motorsport-inspired transformation with our Carbon Fiber Race-Style Rear Diffuser — designed to sharpen rear-end aggression and improve aerodynamic performance. Featuring deep fins and a wide, sculpted profile, this diffuser brings race-ready energy to your daily drive while complementing the clean lines of the B9.5 chassis.

Crafted from 100% premium 3K twill weave carbon fiber, the diffuser delivers exceptional strength with minimal weight. Finished in a high-gloss UV-resistant clear coat, it offers long-term protection and a deep, mirror-like shine that stands out under any lighting.

Precision-molded for a seamless fit to the factory rear bumper, this diffuser adds functional airflow improvements and aggressive street presence — perfect for builds focused on style and performance.

Key Features:

Fitment: Audi A4 / S4 (B9.5) Sedan – 2020–2021

Style: Race-style multi-fin carbon fiber rear diffuser

Material: 100% premium 3K twill weave carbon fiber

Finish: Glossy UV-resistant clear coat for long-lasting clarity

Design: Deep fin layout with widened lower profile for track-inspired styling

Function: Enhances rear-end downforce, improves airflow, and amplifies aggression

Installation: Direct-fit design for OEM rear bumper (may require adjustment for aftermarket exhaust setups)

Upgrade your B9.5 A4 or S4 with a rear diffuser that turns heads and cuts through the air — built for race-day energy, crafted for street domination.