I used the Mequire's Clay system and then used a glaze and finished it off with NXT syn wax and it easily came off the plastic and didn't leave any white residue. Don't forget to go the tails and headlamps which some people don't.
'12 Focus Red Candy SE Sport 5 spd
'99 Toyota 4Runner Sport
'11 Subaru WRX STI Hatch