I've never had to do that to a newer vinyl overlay, but if I were considering it the first place I would call is a body shop. I'm sure they have done hundreds. They're probably down to getting those off in minimum time. I wonder if mfg's. use something like the vinyl wraps kids do today. If so, you might want to inquire about this on a Honda Civic or other boy-racer sites and see what they say. I would think something like WD40 and some heat, like on a really hot day would do the trick. Another idea would be to contact the Bowling Green plant or Museum. Let us know what you find out.