Ok, so I am working on a 70 Trans Am. It is not going to be a numbers matching or concours type of resto but I would like it to look as close to factory body wise as possible. Since it was a Norwood built car it was dipped in red oxide primer. The car is soon to be media blasted and then primed. My question is this, I want the red oxide primer to be visible on the bottom of the car but to do this should I actually use a primer? or some kind of flat base coat the color of the primer. My concern is that if I use an actual primer the undercarriage will not be sealed and therefore susceptible to rot and corrosion. What would you suggest? The car will be driven and stored in a garage but not a climate controlled environment and I live in the Midwest.