Just learned how to restore discolored plastic headlight lenses-

[rzemanfl]

which are a real problem down here. Learned it from the guy who does repairs on my car. I have tried various expensive products with some success but this fix is really simple and cheap. Wet the lens with very soapy water and sand it with 1500 grit sandpaper, keeping the lens wet with that soapy water. Rinse and dry when you are done. I then followed up with a spray of FW1 fast wax (available on the net at http://www.fw1shop.com/) all over the lens, let that soak for half a minute and buffed it. The FW1 alone helps discolored lenses but the sandpaper is like $3.50 for six sheets and really is the key to this fix. I should start a business doing this, but there you have it. The lenses on my '97 Geo haven't been this clear in years. Replacements run about $120 each just for the part, so I'm a happy camper.

[nerddem]

1. yep

my car had ten years' worth of highway chips and the lenses looked like crap. when i got an hid upgrade with some nice hella projectors, i thought about getting new housings, but was rather taken aback by their 630+ EACH price. yikes.

so my gearhead roommate helped me out and we restored them for about 25 bucks, following a similar process, although a little more complicated:
first we wet sanded with three successively finer grits: 800, 1500, and 2000. then we used rubbing compound, followed by a compound called "plastic x" (which also works ok on plastic convertible rear windows), finished off by a regular wax to add some protection. lenses came out looking new!

pictures of the headlight upgrade