Jcsportline Carbon Fiber Rear Diffuser fits Audi A4 B8 sedan-base Bumper 2009-2012(Fit :base Bumper) Fitment:This Rear Diffuser fits for Audi A4 B8 sedan-base Bumper 2009-2012(Fit :base Bumper) Material:Carbon fiber,Made by approved & certified manufacturers with materials that meet market requirements and road use regulations. Installation:This Rear Bumper Diffuser are installed with tapping screws easily. Package:1 pc Rear Diffuser This Rear Bumper Diffuser can Enhance the car's sporty performance ,makes the car more dynamic Please check the item and accessories in the package. Preparatory work(electric hand drill,3MM drill,screwdriver,screws.) Rise the car with lift,dismantle the screws on the bottom of the original diffuser and bumper and remove them. Aiming at the position where diffuser removed,press the clips and ensure diffuser assembly in place(if the clip is loose,can use a screw to fix it.) Install the bumper and the diffuser on the car as a whole by screw then the installation is complete.