I'm getting a small area of rust starting behind each front wheel, (where the cow pies get slung). I'm pleased with the job POR15 did in the bed, so i will just repeat the process in that area. however, i'm not sure how POR15 will hold up to cow crap getting slung on it.. and my reasoning is Cow poo is somewhat acidic, and when left too long with out cleaning off, starts to lift paint, so i don't know how that will affect POR15. what i'm thinking of doing getting steel sheeting with aluminum finish, or a stainless steel sheet and bend it and fit it to the inside of the wheel well to form somewhat of a "splash/splatter" guard to protect the actual frame and sheet metal from further corrosion as well as were I ....there are several places where i could tack weld it to the frame underneath...