I have the bumper skin off my '05 GT... which started out as replacing the burned out 193/T11 bulbs in the headlight fixtures, which lead to removing the fenders... and the bumper skin. So here I am with the bumper skin on my bench, and there's some nasty gouges (curb rash) on the underside... deep through the paint and into the plastic... which I'd like to fix-up while it's off the car. I'm not intending to go whole-hog with a total redo, but would like to fill in those gouges, sand smooth, tape-off and repaint that low lip with some semi-gloss black (the car is black). Does anyone have some plastic filler stuff to recommend?