cleaning haze off headlight covers?

The clear plastic covers of the headlights on my 98 Grand Caravan have a yellowish haze causing the headlights to be not as effective in use. Is there a cleaner (either mixed or purchased) that will remove the built-up haze and restore the covers?

Thanks for all input!

i've used scratch-out on one of my other vehicles' plastic headlight covers. took off a lot of the haze.

Where can I buy it?

Thanks!

i've used scratch-out on one of my other vehicles' plastic headlight covers. took off a lot of the haze.
Try ebay; I bought this same product. Basically it is a very fine rubbing compound. Maybe you would get the same effect if you bought some. Didnt prove to be very effective with my lens.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7913319883&category=33710

Chazage, if there's a CARQUEST store near you, go in and ask for a headlight lens cleaner kit. They run about $50 Canadian (not sure of exchange rate) but works wonders. The kit says it takes about five minutes to do, but if you want the job done right be ready for at least an hour of wetsanding, rubbing compounds and cramped fingers. You could probably pick up a similar kit at any auto parts store, but I'm partial to CQ.

Wet sand with 600 grit then sand with 2000 grit(takes about 5 minutes)then buff with autosol or any metal polish for obout 1 minute and thats it. They look brand new!!!!

Thanks for all help! I'm eager to get started restoring the covers...

I used 1000 grit sandpaper and some clear paint and it did just as good as anything else would do