Audi S4/A4/RS4 B9/B9.5 (2015-2023) Prepreg Dry Carbon Fiber Vented Front Fender

Engineered for Audi S4/A4/RS4 B9 and B9.5 (2015-2023) sedan and Avant owners, this Prepreg Dry Carbon Fiber Vented Front Fender set replaces the factory steel fenders and brings race-grade aero, aggressive sport styling, and front-axle weight savings. Manufactured in Europe and quality-controlled by BYC Performance, this Audi B9 carbon fender set bolts directly to OEM mounting points — no cutting, drilling, or modification required.

If you're building a serious Audi S4 B9 tuning, A4 B9.5 modifying, or RS4 B9 modifying project and want functional vented fenders that relieve wheel-arch pressure, this dry carbon vented front fender set is for you. Autoclave-cured prepreg carbon is noticeably lighter than factory steel fenders, sharpening front-end response and turn-in feel. The functional vents directly aid wheel-arch pressure relief on the RS4 B9's 2.9 TFSI V6 biturbo (EA839) 444 hp engine — shared with the Porsche Panamera 4S — and the S4's 3.0 TFSI V6.

Key Features

• Prepreg Dry Carbon Technology: Pre-impregnated plies cured in an autoclave under high heat and pressure for a more consistent weave.
• Functional Vents: Relieve wheel-arch pressure, reduce aerodynamic drag, and aid brake cooling.
• Significant Weight Reduction: Versus factory steel fenders — sharpens steering feel and reduces unsprung-adjacent mass.
• Race-Grade Strength: Carbon fiber offers very high strength for its weight.
• Aggressive RS-Style Look: Vented design brings A4/S4 styling closer to RS4 aesthetics.
• 2x2 Twill Carbon Weave: Authentic carbon pattern under a high-gloss UV-protective clear coat.
• Direct OEM Fit: Plug & play on Audi A4 / S4 / RS4 B9 and B9.5 (2015-2023) sedan and Avant.

Prepreg Dry Carbon vs. Wet Carbon — Which Is Better?

Most aftermarket carbon parts use wet lay-up, with resin applied by hand and cured at room temperature. Prepreg dry carbon:

• Autoclave-cured under high heat and pressure → a more consistent weave
• A controlled resin ratio → lighter and stronger
• The production method widely chosen in motorsport
• Minimal UV fading over years of use

Vehicle Fitment

This Audi B9/B9.5 carbon front fender set covers all three B9 trim levels (front fender mounting points are shared across A4, S4, and RS4):

• Audi A4 Sedan B9 (2015-2019) and B9.5 (2019-2023) — 1.4/2.0 TFSI / 2.0/3.0 TDI
• Audi A4 Avant B9 (2015-2019) and B9.5 (2019-2023)
• Audi S4 Sedan B9 (2016-2019) — 3.0 TFSI V6 (354 hp) and B9.5 (2019-2023) — 3.0 TFSI V6 (349 hp) / 3.0 TDI V6 MHEV (347 hp EU)
• Audi S4 Avant B9 (2016-2019) and B9.5 (2019-2023)
• Audi RS4 Avant B9 (2017-2019) and B9.5 (2019-2023) — 2.9 TFSI V6 biturbo (EA839) 444 hp, 600 Nm, 7-spd S tronic, Quattro

Important notes:

• Compatible with all three trims because A4/S4/RS4 share the same front-axle and fender mounting geometry. B9.5 facelift did not change fender mounting points.
• RS4 Avant was produced globally as an Avant (wagon) only — no B9 RS4 sedan exists.
• NOT compatible with previous-generation B8/B8.5 (2008-2015).
• The A5/S5/RS5 (B9 Coupé/Sportback/Cabriolet) fender geometry is different; this set does NOT fit the A5 family.

Technical Specifications

• Material: Prepreg Carbon Fiber (2x2 Twill Weave)
• Manufacturing: Autoclave Cure
• Finish: High-Gloss Clear UV-Protective Resin
• Color: Natural carbon weave black
• Origin: Europe
• Contents: Left + right fenders (set)

Installation Notes

Installation requires removing the original steel fenders and refitting on the OEM mounting points. Professional installation required.

1. Partially remove the front bumper to access the fender bolts.
2. Remove the inner fender liner.
3. Detach the original steel fender and disconnect the side marker connector.
4. Align the carbon fender and fit hardware loosely.
5. Set gaps to door, hood, and bumper for even alignment.
6. Tighten bolts in stages to the manufacturer's recommended torque.
7. Refit the fender liner and side marker, then reinstall the bumper.

Care & Maintenance

Wash with pH-neutral car shampoo. Apply carbon-safe sealant every 6 months. Keep pressure washer nozzle at least 30 cm from surface. Periodically check and clean the inner vent surfaces.

FAQ

Are these fenders compatible with the RS4?
Yes. A4, S4, and RS4 B9/B9.5 share the same front-axle and fender mounting layout; this set fits all three trims.

Compatible with both B9 and B9.5?
Yes. B9.5 facelift updated only the bumpers and headlights — front fender mounting points are unchanged.

Compatible with A4 Avant and RS4 Avant?
Yes. Sedan and Avant share the same front fender geometry. Note: B9 RS4 was produced globally only as an Avant.

Compatible with A5/S5/RS5 (B9)?
No. The A5 family has different front fender geometry; A5 owners should contact BYC for availability.

Compatible with previous-generation B8/B8.5?
No. B8/B8.5 (2008-2015) is an entirely different platform.

Are the vents functional or cosmetic?
Functional. They relieve wheel-arch pressure, reduce drag, and aid brake cooling.

Shipping time?
In-stock items ship within 1-3 business days via partner couriers. International shipping available.

Warranty?
BYC Performance offers a 12-month warranty on this product.

Why BYC Performance?

BYC Performance is a Turkey-based performance tuning specialist sourcing premium carbon fiber parts from leading European manufacturers and supplying them to the Turkish market. Our catalog includes Audi B9 carbon parts, Audi RS carbon diffusers, BMW M3 carbon fenders, Porsche carbon spoilers, and many more high-quality carbon components. All parts are sourced from leading European manufacturers and undergo strict quality control.