I'm getting ready to spray paint my belt covers which I had dyed black twice but they never came out black enough. I am going to use primer but I was wondering what the position is on clearcoat. Is it recommended?  I am also thinking of oven baking them since it's pretty humid out.

I used some paint that was for engines which is oil and gas resistant, not specifically for plastic. Held up for over a year with no primer, sanding, or any other effort. Just degreased and went for it.