Is it spray paint? I've had pretty good luck with mineral spirits on a tack rag. Usually the paint is half dry by the time it hits the paint and drys quickly on contact. That means it doesn't stick very well to the wax and grime underneath.
There is a product called autoclay that works great for that. It saved my neighbor's insurance company about 1500 dollars worth of body work after he decided to use his wagner to paint his fence on a very windy day about 25 feet from my jag. They sell it at autozone.