LED Rear Diffuser – Audi A4 S line / S4 B9 Sedan (2017–19)

A gloss black rear diffuser with a center red LED light, for the pre-facelift A4 S line and S4 sedan.

Fits

• Audi A4 B9 sedan with the S line rear bumper, 2017–2019
• Audi S4 B9 sedan, 2017–2019

Does not fit

• A4 with the standard (non-S line) rear bumper
• A4 Avant, allroad or A5 Sportback
• 2020+ A4 / S4 (B9.5 facelift)

Material & finish

ABS plastic, gloss black, with a red LED light.

In the box

1 rear bumper valance with LED light.

Install

Clips in and fixes with your car's original screws (the tape only holds it in position). The LED needs to be wired in. Professional install recommended.

Shipping: Ships with tracking. Most orders arrive in 1–3 weeks.

Every part is direct fit, with no cutting. The product details above say how this one mounts: tape, clips or screws.

Before you peel any tape: test-fit the part, clean the surface with isopropyl alcohol, and install above 60°F so the adhesive bonds. Lips, splitters and diffusers take longer and may need small pilot holes, and LED parts need wiring, so we recommend a professional install for those.

Not sure it's right for your car? Message us your year and trim before you order.

Every order ships with tracking. Most orders arrive in 1–3 weeks. Parts marked "Ships from a US warehouse" usually arrive faster. Spoilers, lips and diffusers ship separately because of their size.

Fitment guarantee: if a part doesn't fit the car and years it's listed for, contact us before installing and we'll refund you.

See our Shipping Policy and Refund Policy for details.