The wheel wells are fitted with plastic liners. These liners help to keep water and debris from entering body panels, electrical components and the engine compartment. The wheel well liners also help to reduce road noise and offer another level of weight reduction by reducing the amount of metal used in the fenders and surrounding components. This article will show you how to remove the rear portion of the rear fender liners, which will give you some access to the intercoolers.
Lift the rear of the vehicle and support it securely on jack stands. Remove the rear wheel(s). Remove the two 10mm plastic nuts (yellow arrows), and the four T25 Torx screws (green arrows). Pull the fender liner out of the fender by grabbing the interior edge (blue arrow) and pulling it off the mounting stud first. Then tilt the fender liner forward and guide it out of the fender.