2017–2019 Audi A4 B9 Base Sedan Carbon Fiber Rear Bumper Diffuser

Product specifications

Carbon Fiber Rear Bumper Diffuser for 2017–2019 Audi A4 B9 Base Sedan

Carbon Fiber Construction

The diffuser is produced with 3x3 woven carbon fiber and finished with a gloss UV-protected clear coating. The exposed carbon weave is designed to complement other carbon fiber exterior upgrades while creating a more distinctive lower rear profile.

The UV-protected clear finish helps protect the visible carbon surface from normal environmental exposure while maintaining its gloss appearance.

Replacement-Style Rear Diffuser

This is a replacement-style rear bumper diffuser rather than an add-on lip. The factory lower diffuser is removed before the carbon fiber replacement is installed in its place.

The design follows the lower rear bumper area of compatible A4 B9 Base Sedan models and is intended primarily as an exterior styling upgrade. No specific downforce, drag reduction or handling improvement is claimed unless supported by product-specific aerodynamic testing.

Installation

Installation involves removing the factory rear diffuser and fitting the replacement carbon fiber unit. Self-tapping screws are included according to the current product specification.

Test-fit the diffuser before final installation and confirm that all mounting points and edges align correctly. Professional installation is recommended, especially if you are unfamiliar with bumper trim removal or panel alignment.

Confirm Your A4 B9 Rear Bumper Before Ordering

This product should be ordered based on the actual rear bumper configuration rather than model year alone. It is specifically positioned for the 2017–2019 Audi A4 B9 Base Sedan and should not be assumed to fit S line, S4 or later B9.5 bumper designs.