I did not use primer on mine when I painted the entire engine bay. I used a piss ton of degreaser, scouring pads, and elbow grease. Taped everything up that I needed to, and then wiped everything down really well with some prep solvent (rubbing alcohol)
I used Rustoleum Professional Enamel in gloss black. Came out flawless.
I remember clear-coating it, but I can't remember what I used, probably Rustoleum, but not 100% sure.
Didn't take any good pictures of it. But this was a before picture (probably a 6month before, but it still works)
and this is the only after picture I have that shows it off any
