I've been doing headlight restoration professionally for 3 years now. The kits that you buy for $15-$35 in the store don't quite get the job done as well as someone like myself can, but I am an auto enthusiast first and foremost so I know the satisfaction of the completed DIY. Keep in mind that you need to keep up on your lights or they will return to the previous state. Not sure how much plastic polish comes in those kits but at least once a month apply some via hand or buffer to your lights to keep the clear, lustrous finish.

I picked up the 3m kit at work for $12 with $3 mail in rebate and used it on the jetta. I've hand sanded lights before but man this was easier and really did work better. well worth the money. I disassembled the housings, did both sides of the lense, and lexan'd them back together. night and day difference. literally.