This question comes up a lot, and you'll most likely get a bunch of different answers..... I had to give up on one kit (a T Bird molded in red) because of this reason. I finally figured that the only way to keep the dye from coming through was to use craft paints on it, as they're not 'hot' like a lot of spray cans can be...... I'll still build the Thunderbird kit eventually, but it will have to wait until I get an airbrush setup..........