Apologies for a question which must have arisen many times before but I need to clean up a few scuff marks on the running boards of my 22 Plus Four. I'd prefer to blame the previous owner but in truth I know I'm the prime culprit but when I've looked at scuff repair solutions on line a number of them recommend caution which has so far deterred me from trying. My first feeble attempt with a j cloth and a drop of acetone left more scratch marks than I'd started with so any suggestions would be greatly appreciated.