Audi A4 S-Line / S4 B9 Rear Diffuser – Prepreg Dry Carbon Fiber (2020–2021)

If you're building your B9 the right way, the rear end matters just as much as the front. This Prepreg Dry Carbon Fiber Rear Diffuser is designed to give your Audi A4 S-Line or S4 a sharper, more aggressive finish that completely transforms the rear profile. The 3D-contoured design adds depth, dimension, and true performance-inspired styling — giving your build that finished, high-end look it deserves.

Crafted using advanced prepreg dry carbon construction and autoclave curing, this diffuser delivers exceptional strength with lightweight performance. The deep gloss epoxy finish enhances the carbon weave clarity while protecting against UV exposure and surface wear. Whether you're going for a subtle OEM+ upgrade or a full performance aesthetic, this diffuser ties the entire rear bumper together with precision styling.

Features:

• Prepreg dry carbon fiber construction
• Autoclave cured for superior strength and weight reduction
• Precision 3D aerodynamic styling
• High-gloss UV-protected epoxy finish
• Lightweight and durable design
• Direct rear bumper fitment

Content:

• 1x Rear diffuser
• Mounting screws included

Fitment:

• 2020-2021 Audi A4 S-Line (B9)
• 2020-2021 Audi S4 (B9)

Specifications:

• Material: Prepreg Dry Carbon Fiber
• Position: Rear Bumper
• Finish: High-Gloss Clear Epoxy
• Style: 3D Performance Design
• Condition: Brand New
• Warranty: 1 Year

Shipping Information:

• Processing Time: 2-5 business days for warehouse stock items
• Made-to-Order: Please allow 2-4 weeks for shipping if product requires custom manufacturing

Upgrade your B9 with carbon that speaks for itself. Clean lines, aggressive styling, and premium construction — this is the rear-end detail your build has been missing.