This original thread cutting metal nut attach heat shields underneath the floor and in the engine department, on to studs. They tend to rust and get destroyd after all these years. It does fit various places on the vehicles in the list below. Price is for one nut.
Fits: Audi coupe, S2 coupe, avant or sedan , RS2, A4, A4 quattro, S4 and RS4 B5 sedan and avant, 50, 80, 90, 100, 100 quattro, C2, C3 and C4, 200, (UR)quattro and Sport quattro 1977-2002 + many more. Referance for original Audi parts numbers: N0386011 , N0386024 and N0386015