The Audi A4 bumper cover is also called as the Audi A4 rear bumper within industry circles. The accessory is a type of plastic that bolts onto the lower rear portion of a car. The Audi A4 aftermarket bumper can be found attached to cars in abundance courtesy the convenience that it provides and the easy purchasing of trendy aftermarket options. The Audi A4 custom rear bumper is mostly designed from the best hand laid fiberglass available in the market and has the mettle to endure the brunt of car collisions. The bumper also contains a cut-out to allow the exhaust tip to leave the automobile. The primary material is carbon fiber that is used for the Audi A4 carbon fiber rear bumper while ABS plastic acts as the secondary one. The bumper is touted to be highly efficient.