T Cut or any scratch remover should get out light marks. A good product, used by the trade and available to retail is Farecla G3 and G10. G3 is a bit harsher for deeper scratches, G10 is for the lighter stuff and finishing off after G3. With the more paste type compounds, use with water, preferably sprayed on to the bodywork to rub the paste in and smooth it out. If you get white powder residue on any plastic trims, the best stuff I've found is Vanish, in the pink bottle. Spray that on and work it on, buff off with a fresh cloth. You can work it in with a tooth brush if you need. Also great for getting dirty stitching on steering wheels and door handles clean.