What to use for truck running board paint?

[DD931]

Been doing some research. POR-15 seems to be a good choice, but may be somewhat UV susceptible. So, POR now offers POR-15 TOP COAT, which is specifically UV resistant. Apparently the thing to do is use POR-15 regular stuff for a couple of coats and the put a coat of TOP COAT over that. I think that's the path I'm going to follow. It should be a lot cheaper than powder coating!