I put it both under and over. Under to give a smooth level surface and over to seal them in and level the decal with the paint. You can just overcoat as most car finishes are glossy and just fine for decals. If you want to see a sample of the under/over clear coat look up my Kurtis Kraft racer in the review section of this website. The clear coat I used was from testors. Hope that helps.
Yes, it does...thank you