[Cartman]

Are you using a plastic parts primer or a standard primer with flex agent? some plastics are especially a pain in the a$$ when it comes to painting. clean the part with soap and water first, then a plastic prepping/cleaning paste (dupont, SEM, PPG all offer some kind and are available at parts stores that have paint) then scuff using waterbased wax and grease remover (prefferably made by the same company as your paint system). use a waterborne plastic primer. these are usually 1K primers and are nonreactive to plastics. once that primer is dry, you can go over it with standard flexiblized sealer and base/clear. dont wait too long between base coat and clear coats. the most dry recoat time ive seen with paint systems is 12-20 hours, any longer than that you will have delamination problems with the clear down the road. saturns have plastic parts that are a pain like this, but when you prime with that waterborne, you have no issues. good luck and hope this helps.