my 91v6 firebird has exhaust that looks like stainless steel. its not to rusted BUT its rusted inside and around the tips a little bit. i dont think it sounds stock cuz ive heard stock and it has numbers from a marker on one of the pipes too...did gm put this exhaust on my car or is it some kind of aftermarket? my dad said they make cheap stainless steel exhaust that has a rep of rusting inside.