Mr. Ch, Are you asking if you should prime the clear plastic lenses? If so, I suggest that you do not prime them. You'll destroy the very reason for having the clear lenses. They need some opaqueness to give them the sense of depth and light refraction that you get normally from the glass of a headlight. Priming them will destroy that. Use a transparent red on the clear lens of the tail lights. Tamiya makes a perfect one. It is formulated to be opaque. Do not prime first. If you're worried about adhesion when you paint on the transparent red, wipe the lenses with alcohol first to remove any contamination. Those little pieces will not peel, partly because they'll never be handled and also because you'll be applying a very thin coat. You can paint the inside of the headlight, not the lens, in a light grey to help give some color to the lens as you look through it if you want to. But do not paint the lens. Barrett