When using Rustoleum, I only use the “Professional” High Performance Enamel that is easily identified on the store shelves because it only comes in the tall spray cans. I started using it some years ago to touch up repaired areas on race car frames. Dries much quicker than regular Rustoleum spray and it is very resistant to gasoline. It was even more durable than the original powder coating on the frames. This paint can be top coated with solvent based clears when thoroughly cured. Only down side I could see was slightly reduced gloss than the regular spray and there was a smaller color selection.
Overall my paint of choice is Klass Kote. When clear topcoats are necessary, automotive 2 part urethane is the choice. Neither of these are really compatible with a spray can enamel like regular Rustoleum.