I dipped my whole crossfire and my taillights are dipped as well. What we did was halfway through the dipping process (Coat 4) we used an Exacto blade and cut the dip where the taillights are. There is a shallow indent around where the lights are and we traced that to make sure we would get a good break in the dip so when we peeled off the section covering the lights it wouldn't rip the rest of the dip and we would have to start over. This worked perfectly and we continued painting like we normally would. With only 4 coats on the actual lights and 8 everywhere else. I haven't had any complaints. Even in the day time people can see my lights, the only person who said they had trouble seeing was one of my troops and he said he probably had difficulty seeing because he is color blind.

Hope this helps!