That seems a little excessive haha... but better safe than sorry, I suppose. I did one and a half coats of paint (really high quality stuff) and no primer. I guess I figure if it's covered, it's not gonna be getting hit by rocks and stuff, so it should be fine.
My friend that helped me did his the exact same way and it hasn't been a problem for a year and a half or so, so I'm not too worried.
In retrospect, we probably should've sanded and primed and used hi-temp paint, if for nothing else than peace of mind. But I think it'll be fine. If not, we can always just take them apart and do it again. Haha.
Everybody's lights look GREAT.