2020–2021 Audi A4 S-Line / S4 B9 Rear Diffuser – Pre-Preg Dry Carbon Fiber
SHIPPING - RETURNS - WARRANTY - CANCELLATION POLICY
*** Market Conditions after 2020 have changed the landscape of automotive parts. Although we try to stock 1000's of items in our multiple warehouse and use multiple distribution channels, having back-orders are unavoidable in today's market. If you are in need of a product quickly, we suggest email, message, or call us for availability so that we may explore your options.
Email: Sales@Speedzoneweb.com
Call: 407-846-8430
Text: 407-749-6314
Frequently Asked Questions
2020–2021 Audi A4 S-Line / S4 B9 Rear Diffuser – Pre-Preg Dry Carbon Fiber
Give the rear end of your Audi A4 S-Line or S4 B9 a sharper, more aggressive finish with this pre-preg dry carbon fiber rear diffuser. The 3D-contoured design adds depth and dimension to the rear bumper for a performance-inspired, high-end look.
Build
- Material: Pre-preg dry carbon fiber — the resin is pre-impregnated into the weave under controlled conditions before autoclave curing, giving exceptional strength with lightweight performance, a consistent weave, and a lighter finished component than standard wet carbon
- Manufacturing: Autoclave cured, precision 3D-contoured for accurate fitment
- Surface finish: Deep high-gloss clear epoxy finish that enhances the carbon weave clarity and protects against UV exposure and surface wear
- Configuration: Single-piece diffuser for the lower rear bumper
Design & Aerodynamics
- Aggressive stance: 3D-contoured diffuser profile adds depth and dimension to the lower rear for a more planted, performance-focused rear end
- Carbon aesthetic: Refined dry carbon weave and high-gloss epoxy finish deliver premium contrast against the factory paint
- Factory-style integration: Precision-molded to the contours of the factory rear bumper for a clean, seamless fit
Fitment
- 2020–2021 Audi A4 S-Line B9
- 2020–2021 Audi S4 B9
- Fits the A4 S-Line and S4 factory rear bumper only — not compatible with the standard non-S-Line A4 or aftermarket bumpers
Package Contents
- 1 × pre-preg dry carbon fiber rear diffuser
- Mounting screws for installation
Installation
- Screw-mounted: Secures with the included mounting screws for a secure, rattle-free fit
- Drilling required: Screw fixing pierces the bumper, so this is a permanent modification rather than a reversible fit
- Surface prep: Clean and degrease the rear bumper at the fixing locations before installation
- Alignment: Dry-fit and check the diffuser sits centred and even across the bumper before driving any screws
- Professional installation recommended for correct positioning, panel alignment, and a clean finish
Before You Install
- Confirm your car is an A4 S-Line or S4 B9 (2020–2021) before ordering — this will not fit the standard non-S-Line A4
- This is a permanent, screw-mounted fitment — dry-fit and confirm placement carefully before driving any screws, as holes cannot be undone
- Take care when parking rear-in — lower rear panels sit close to kerbs and parking blocks
Our History
For 26 years Speedzone Performance LLC has been providing aftermarket car parts to Central Floridians and 1000's of customers online. What makes us different than all the other places online? We have 3 actual brick and mortar locations where were serve customers daily and find new ways to provide support and assistance to the automotive community at large. From our in house SPDZ1 Brand, to our constantly growing in stock inventory, we strive to make our customer service and ease of purchase stand out from the rest! We are also one of the largest automotive part financing providers anywhere in the United States, and continue to provide more options for our customers every year. We love what we do, and it shows in every product we sell and every new customer who becomes a part of our Speedzone Family.