Has anyone bought any of the ones advertised? What works what doesn't? Anyone have any before and after pics?

The ones that go on a drill? I've never tried on, I use my porter cable and some polish. and that does a great job. I don't see a drill having enough power, but I guess with enough time I would clean things up.

haven't had good luck with the kits out there from the auto parts stores. they last a very short time and have to redo them almost every week. i use this stuff works awesome!

Second for the Porter Cable doing a great job. On really bad headlights, I've started with wet sanding and then buffed with the P-C. One way to make them last longer is to use a UV sealant after you've done the buffing. There are all kinds of expensive UV sealants for headlights, but is mix 1 part Minwax Helmsman Clear/Gloss Spar Urethane with 1 part Mineral spirits and applied it to the headlights with a blue shop towel.

So the process is wet sand, buff, clean headlights with alcohol to remove buffing compounds and apply the urethane mixture with a shop towel.

X3. It has always worked for me.