I always just start with an adhesion promoting primer. It will make regular paint stick to pretty much anything. I've always got it from auto parts stores.
- Make sure to clean the surfaces good. Paint prep works well, but isn't necessary.
- If you are going to paint the inside, paint the inside first.
- Paint each panel individually. Do not have panels near each other when painting others, as the over spray will end up on them.
- I try and paint when it's cool out (not cold) so the paint takes longer to dry. This way I can get the entire piece wet at once. This makes sure it ends up glossy.
- Definitely plan on clear coating it if you want the "wet" look.
- Make sure you read the label on the paint you choose. Some need to be re coated almost immediately or wait until the paint is entirely cured, which can be anywhere from 24 hours to 2 weeks.