Roll bar painting question?

[cad]

I also used Rustoleum, but didn't thin it and the foam brush drug the paint around alot. Sort of like streaks. A painter that I know said that I should have thinned it out a little and it would not have done that.
It turned out very nice after a second coat.
No primer. I cleaned it with Acryliclean wax/grease remover.