Part number 3880494 Nuts were ONLY used in 7 places on each side of a factory side exhaust car. They were used for the attaching screws on the cover, and also the front bracket of the exhaust cover where it is screwed into the wheel well area. They are unique as there was no other application in the GM parts system for these items. These are new reproductions of the original part. There has been no correct reproduction of these nuts, just a generic version u-nut that has a hex steel nut instead of the square nut like the original. Judges look for these! Get those extra points! Note the "M" logo on each nut.