But most cars are not immersed He may be right MauganH17 about it being really tough in the car environment...but most cars are not immersed in salt water...or even exposed to the salt air environment that a cat trailer is...like I said all it takes in one little nick, gouge, place where it didn't get completely coated and its going to start rusting...beside most of those car guy are really anal about keeping their babies super clean.They would never have a chance to rust anyway...