Lubricate door hinges and check their mechanisms so that the vehicle does not creak and groan normally, as the chassis flexes over uneven road surfaces. Oil the door checks and hinges both sides of the car. Use oil on the upper hinge and lower hinge on both sides. Further, apply grease on the hinge parts and check operation. For reference only, Audi part numbers. Always check with your parts department or aftermarket parts specialist for current parts info.