I found some of my CDs in a box that had been rolling around in the back of my daughter's car. They were pretty scratched up and skip a lot. I googled "fix CDs" and got lots of stuff that look like scams. Some of the "fixes" they recommend I'm sure could ruin the surface (emery cloth...errrm, not so sure...). So what works? If possible I'd like first-hand experiences with this.