there was supposed to be a special coating on the throttle plates ou our cars too...if it was there, it didn't do crap. so don't worry about ruining it. I don' tknow about using carb cleaner on plastics though...i don't think it'll hurt, but why don't you grab a piece of scrap and test it out?

1999 Silver Frost SVT #609 of 2760 Quaife, lightened SVT Flywheel, SPEC stage II clutch, removed resonator, k&n drop in - various other goodies too.