It would be tough to make it worse. What I showed is yes straight from that can and no I don't plan to clear it. Black is the one color you can match with one can. Its available in full gloss with UV protection unlike other colors and metallics. Single step would work OK on white or red too but won't match like black does.
When I painted the front license hole cover, I did clear that for max shine. Heavy sanding and buffing of spray paint should be avoided in my opinion. Spray your black while moving the can fast and holding it close to the surface. Overlap plenty with each pass and make an effort to keep the fuzzy edge small while wetting the color area well.