OMG hell why not just take a sand blaster to it. I agree though some very fine sandpaper if the clearcoat looks tarnished or some 00 steel wool in one spot to test out to see if this clears it up. then cme back with some kind of compound/polish.
you can use red scotchbrite, 1500 or 2000 grit wet sandpaper. then you have the choice of repainting it, clearcoating it, or polshing it, but beware after you scuff it up it will take hours to get it back to looking nice. you can use a buffer also white wool or foam only, yellow wool is for rubbing compound, white is for polishing compound. pm me if you want more info.