Take "Purple Power" cleaner degreaser you get at the auto parts store in gallon size. Pour it into a tupperware tub deep enough to submerge the body. That stuff will lift the paint without warping the plastic. Leave the car in there for a day or so. Once the paint bubbles up you should be able to just wipe it off. Then wash the body off with soapy water, wipe off, let dry, then you should be back to bare plastic.