I used a flexible urethane bumper repair kit, to fill in my 'Mustang GT' embossing on the side skirts. It came in a two-part (epoxy type) tube. The area was well prepped, and sanded down with a rotary disc etc. Just be careful, as the skirts are very thin, and you do not want to sand through! The product (SEM, I believe) was a PITA to work with, as it was somewhat thin, and we had to keep working it back up, into the embossed letter area, as gravity kept pulling it out. Once it began to tack up, we quit f'ing with it, and it set up nicely. A bit more sanding, and the absolute thinnest coat of body filler did the trick. Mine has been on the car, for over 6 months, with no issues! -- fingers crossed, lol!