It`s not that simple when it comes to preparing panels for respraying. If you`re going to prime your already painted plastic parts p320 dry at least is recommended for the primer to achieve adhesion. Then there are 1K and 2K primers. With 1K being in a can, 90% consisted of thinner, which has very limited application potential when it comes to serious body work. If plastic parts are to be painted a different procedure must be followed prior to priming and/or spraying. Moreover if any bodywork that involves putty is required for smaller or bigger dents and extensive scratches p150 and p240 sanding is a must. Tools also very important, sanding machines etc. I can take a few shots tomorrow from work to give a clue of what i`m talking about.