Rear Bumper Diffuser Dry Carbon Fiber for 2021UP Audi S4 A4 Sline B10

Dry Carbon Fiber Rear Bumper Diffuser for 2021+ Audi S4 / A4 S-Line (B10, Sedan)

The Audi A4/S4 B10 (2021+) introduced a revised rear fascia with a more defined lower bumper diffuser section — the B10 S4 and A4 S-Line's rear bumper incorporates a structured lower diffuser opening that is architecturally distinct from the B9's rear bumper. This dry carbon fiber rear bumper diffuser is a direct replacement for the factory plastic diffuser panel on the B10 S4 and A4 S-Line, replacing it entirely with genuine dry carbon fiber. Unbolt the factory diffuser and mount the carbon unit using the factory screws — a complete direct replacement with no modification to the rear bumper structure. Professional installation recommended.

Why Dry Carbon for the B10 S4/A4 Diffuser?

• Direct Audi RS and Competition Package Standard: Audi Sport's own carbon exterior packages on the S4 and RS4 use prepreg dry carbon fiber for rear diffuser and bumper trim components — this diffuser matches the same construction method, delivering surface quality consistent with Audi Sport's carbon exterior standard.
• Thermal Resistance at the Rear Bumper: The B10 S4's rear diffuser sits in close proximity to the TFSI exhaust system. Dry carbon pre-preg's lower resin content makes it inherently more heat-resistant than wet-lay alternatives in this rear bumper position.
• Direct Replacement, Factory Screws: Mounts to the factory B10 rear bumper attachment points using the existing factory screws — no new hardware required beyond what's already on the car.

Key Features

• B10 S4 & A4 S-Line Specific Fitment: CNC-moulded and real-car tested for the 2021+ Audi S4 Sedan and A4 S-Line Sedan (B10 platform). Direct replacement for the factory B10 S-Line/S4 rear bumper diffuser using factory mounting points and screws. Not for B10 A4 Base or B9 platform.
• Direct OEM Replacement: Unbolt the factory plastic diffuser and mount the carbon unit — no modification to the rear bumper structure required. Complete replacement panel.
• 100% Real Prepreg Dry Carbon Fiber: Genuine dry carbon pre-preg construction — not wet-lay carbon, not FRP. 3×3 twill weave surface with UV-gloss double-layer clear coat.
• UV-Resistant High-Gloss Finish: Double-layer anti-UV clear coat locks in carbon gloss and resists fading and discoloration over time.
• Export-Grade Packaging: Multi-layer shockproof export carton (14 kg gross) ensures safe delivery across international shipping routes.

Product Specifications

Note: Fits 2021+ Audi S4 Sedan and A4 S-Line Sedan (B10 platform) only. Not for B10 A4 Base or B9 (2016-2020) platform. If your vehicle has a rear parking sensor door, contact us before ordering. Professional installation recommended.

Replace your B10 S4/A4 S-Line's factory rear diffuser with genuine dry carbon fiber — add to cart or contact us for a fitment and sensor compatibility consultation.