A4 / S4

Audi A4 / S4 B9 and B9.5 carbon fiber parts

On a B9 Audi A4 or S4 you can fit a carbon front lip, front canards, a vented hood and front fenders, and swap the mirror caps for carbon fiber ones. For the facelifted B9.5 there are also a rear diffuser and fog light surrounds. Every part is prepreg dry carbon fiber, and BYC Performance imports them from leading manufacturers around the world.

Front bumper: lip, canards and fog light surrounds

The front lip extends the lower edge of the bumper downwards. The front canards are small fins that mount on the bumper's outer corners. The two are sold separately, so you can choose one or both. They are marked B9 / B9.5 and made for A4 and S4 bumpers; the RS4 has a different front bumper. The B9.5 also has its own fog light surrounds.

Hood and front fenders

The vented hood and vented front fenders are full panels that replace the originals. You can change the hood on its own or together with the fenders. Both are listed for the B9 and B9.5 and have RS4 in their titles. The RS4's front fenders are wider than those of the A4 and S4; if your car is an RS4, confirm fitment on WhatsApp before you order the fenders.

Mirror caps and rear diffuser

The mirror caps fit the A4, S4 and RS4, and also the B9 and B9.5 A5 / S5 and RS5. There are two versions, for mirrors with and without blind spot assist, and you pick the one that matches your car when you order. The rear diffuser fits the lower section of the rear bumper and is for the facelifted B9.5 A4 and S4 only.

Frequently asked questions

Are the parts different for the pre-facelift B9 and the B9.5?

The chassis code in the product title tells you. Parts marked B9 / B9.5 are listed for both versions, while the rear diffuser and fog light surrounds are marked B9.5 only. The A4 also has different standard and S line bumpers, so before you order the front lip or canards, share your car's model year and bumper type on WhatsApp.

Does it fit the Avant?

The Sedan and Avant have the same front bumper, hood and fenders, so the front parts fit both. Their rear bumpers are different, so before you order the rear diffuser, tell BYC on WhatsApp whether your car is a Sedan or an Avant.

Does it fit a B8 or B8.5?

The parts on this page are for the B9 and B9.5 only. The B8 and B8.5 are the previous generation and have different body panels.

What is the process after I place an order?

Lead time for sourced-to-order parts is confirmed on WhatsApp right after your order. Parts ship via partner couriers, and each part has a 24-month BYC warranty against manufacturing defects.