Rustoleum?
Just spray it on in thin coats. It'll run pretty quick on you if you try and cover in one or two coats. I do it all the time. Even paint trim moneykote, ultracoat and solartex. I use 15% fuel most of the time. Standard surface prep should be followed. Clean, light buffing to give the paint something to stick to. Although I've had pretty good luck without any prep work done.
Edwin