What I would do....
My wife owns a sign company. She uses this stuff called "Rapid Remover" for removing vinyl decals and anything with an adheisive backing. The actual substance is non-toxic and smells like citrus. But damn, the stuff cuts through anything that is plastic adheisive like butter. I bet it would be safe on your seats and dash. Remember, most paint is just plasic. You can probably find this stuff at any local sign shop supplier. Good luck!