This is the second time I've used this kit (costs about $20 at your local parts store -- Autozone, Oreilly, etc.).
I was very impressed with the results on my old 2003 PT GT. Before the kit the headlights looked awful so I used the 3M kit which made them look brand new again! A year and a half after using the kit the headlights still looked new.
Over the weekend I decided to do the same thing to my 2006 Crossfire Coupe. The headlight lenses looked terrible and again I am extremely impressed with the finished product. The lenses look brand new again and hopefully the results will last as long as they did on my PT GT's headlight lenses.
The kit is a several step process that requires a 1200-1600rpm drill. It includes various grits of sandpaper (500, 800, and 3000 wet) that velcro to the pad that attaches to the drill. The final step is a buffing pad with 3M's rubbing compound. Be careful though and follow the instructions if you do the same because if the kit is used improperly you can damage the headlight lenses permanently.
Here are some before and after pictures... sorry for the poor quality, they are from my phone as I could not find my digital camera cable.
Before:
(the white spots are not really reflections they are spots that are so yellow you cannot see through the lens)
Beforeheadlight.jpg
After:
(Looks brand new again!)
afterg.jpg