Novus Plastic Polishhttp://www.novuspolish.com/
The Container Store (HQ in Texas) carries this product in their stores.
Some plastics are coated with a thin film which may be damaged by the abrasives in the polish.
NOVUS No. 2 and No. 3 Polishes are not recommended for use on coated plastics or eyeglass lenses.
The type of polishing cloth you use will make a difference. The ideal cloth is nonabrasive, absorbent and lint free. To eliminate any chance of scratching, use only disposable cloths. Reusable cloths can retain abrasive particles, but you won't know for sure until the damage is done. Use a soft cotton cloth (such as a diaper), avoid using polyester or rayon wipes which can scratch unprotected plastics.