I used NAPA primer, Duplicolor paint and top coat. I did about 20 coats of paint, and it turned out awesome. My friend has a monster truck. He went through all sorts of paints and primers to figure out what worked. He pained his doors, they're always getting kicked at b/c that's the only way you can get out. Anyways.... use the NAPA and Duplicolor combo... his hasn't chipped in a year.