I love the useful 4.5 year old threads. Well, I had the hazy headlight problem on my 98 camry and searched the web for help. This seemed to be the best thread so I tried using a plastic polish (turtle wax, I believe) hoping for the best. It seemed to help a very small amount but the lenses were still very hazy and didn't give much light on dark nights. My brother even commented once saying it was dangerous!
So, I thought about the silverstars but then read about them causing yellowing inside the lenses from the extra heat and that they burned out quick. So, I did nothing for months. I ran across another page mentioning a method using extremely fine sandpaper which seemed promising but I wasn't sure where to get it so I gave up.
Finally, I ran across a car maintenance site that just happened to mention a commercial product called Crystal View. They sell it at places like walmart, kmart and advance auto now so even though its a bit overpriced at 20 bucks, I bought it when getting oil yesterday.
Basically it has you wet sand the lenses with 1000 grit, then one even finer than that maybe 2000 grit. Next you buff the lens with "secret liquid #1" which seems to be a liquid plastic polish of some kind - very slightly abrasive to finsih off the polishing. After thoroughly rinsing and drying you put on a coat of "secret liquid #2" which seems to be some kind of liquid plastic sealer - you just wipe across the lens to wet it and let it dry. It really seems to take the haze out that all the previous sanding left.
Anyway, when its all dry the results are amazing. They really do look like new and they have a lifetime warranty. I know this might look like some kind of ad being my first post and all. I've lurked a long time and just wanted to offer a solution for those a little lazy!
Here's their site if you're interested:
www.myheadlight.com
If cheap, try searching for a method similar using ultra fine sandpaper. I can't remember where I found it but it probably is a little more specific on products used other than the sandpaper so you can replicate this method.