Do Headlight Restoration Kits Work?

I see products advertised on TV that look so cool in the commercial but wonder if they really work. I have been seeing an ad for a headlight restoration kit. I have a car that has headlight covers that are so cloudy and yellow that I can barely see them. I decided to give Mequiars Headlight Restoration Kit a try. I found it at my local Walmart for about $20.

The box has a cloth, a bottle of cleaner and a disc pad to fit on your drill. You just put a dab on the pad and buff the lens cover then wipe it clean. It is very easy and I have to say, I THINK it worked. I can't really tell for sure. There is not doubt it took away some yellow and cleared it up a little but I was expecting a bit more. As you can tell from the photos, it certainly looks better. I will take it out for ride tonight and see if the lights shine a little brighter.  I would give it a B grade.