I had a gas stain on my car from a leak in the back. What my friend suggested me to do is get really fine sand paper (2000 grit) and a bucket of water. Wet the sand paper quite a bit, i recomend leaving it in there for a minute or two. Then, lightly rub in circles on the outside of your car, do complete sections. When finished, rub in compound, buff it, then wax, buff. Worked like a charm. My car was never so shiny