There is a thread about the proper way to tint your tails. You need to clean the lights with a degreaser or something to get a proper base. After that, sand the tails before you do anything. Wipe off any dust or grit from the sand paper. I believe I sanded mine with 1500 grit. Then spray your first coat. Sand in between coats and when you are done spraying the tint, spray your clear. When I did mine, I didn't sand the clear at all. I was very happy the way mine turned out.