I painted the entire chassis, frame, and floor pan of my '56 Cadillac with Rustoleum Semi-Gloss Black in rattle cans. That was 20 years ago and I have not experienced peeling or flaking or any paint failure whatsoever. This car gets used all time as regular transportation. I did not use primer.

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)