Replacing the rear fender panel (Audi 100 C3)

Drill out the contact welding races. Clean the mating surfaces with a grinder. Apply zinc-containing primer to the surfaces to be contact welded. Adjust the new wing and install it, ensuring the required gaps. Contact weld the wing around the perimeter and weld the holes at the junction of the wing panel and the pillars with arc welding in a protective environment (front and back) side glass opening (back door). Apply sealant and restore the protective coating of the rear wheel arch. Treat the internal cavities with liquid wax.