First of all, and most importantly imo, gotta get the surface nice and clean to prevent any imperfections and remove any dirt and oils. My first one I didn't clean well and got wrinkling. I also did mine with adhesion promoter, duplicolor body color and clear coat. I washed my vents with simple green then wiped them down with denatured alcohol. Then lightly sanded with fine grit(600-800) sand paper and washed again. Applied a couple light coats of promoter and did 3 or 4 LIGHT coats of body color and then 2 or 3 coats of clear. Make sure to let proper dry time between steps. You can also wet sand in between coats but I didn't have days. This is just the way I did it and only a suggestion. If you ask 5 people how to, you'd probably get 5 different processes.