Well I just thought I would post this information here.
There is a new paint out by Krylon that is called Krylon Fusion spray paint for plastic. It doesn't require any sanding or priming and it sticks to plastic. It is supposed to dry in 15 minutes or less. This link has several different colors to choose from.
This would probably be a good type of paint for those custom mandalores out there.
Hope this helps someone.