The whole problem with smoking out tail lights is you gotta take out the whole assembly, and THEN, you need to take off the red lense cover, without breaking it. I think that would be the hardest part as they often aren't meant to be removed and then put back on. Chances are it will no longer be watertight after this. Then you would spray the smoke stuff on the inside of the lense, and then pop the red lense cover back on and reinstall. I'd like to see some pics after its all done, if anyone actually does this. Maybe it would look good with my LEDs.