Looks like it is inside humidity. But if you are 100% the matter is outside you should use Meguiars Plastic Cleaner before any sanding. If the damage is too big you may then sandpaper with much dishwasher, use 2000 grit. Then polish with the Meguiars and at least weekly apply wax to avoid return of debris and protect against solar UV rays. I do it almost daily with our customers locally. Good luck! WWW.SAGAHID.COM

At the body shop I work at we get those a lot, what we do is wet sand with 800, 1000, and 1500. then we just put 2 coats of clear coat on it, so the haze won't ever come back and you can wax the headlights so they will be extra shiny :)
we charge about $75 a headlight. Check your local bodyshops for prices.

Or you can try using FLITZ metal polish. Works great on removing haze. Follow that with a little wax and you are good to go.

I would used PlastX. They worked great for me! I wetsanded mine but the biggest difference came when i used the PlastX. It's only like $8 so it wouldn't hurt to give that a try before doing anything else.

am i the only who uses plastx everytime i was the car?

This stuff works :thumbup:

LOL No, you're not the only one. I clay bar the lense, buff it with PlasticX followed by Aerospace Protectant 303, cause it has UV protection. My lenses are crystal clear.

It says its for paint. But you used it on the plastic lens and the rest of car? If so Ill pick it up and do my whole car....

Wolfgang will work.

http://www.wolfgangcarcare.com/heleca.html

http://us.st12.yimg.com/us.st.yimg.c...2021_101537340

mine's got the same dilio on the inside of the headlights.. is there a DIY of cleaning the inside?

I would imagine it would be the same cleaning process described here combined with the headlight disassembly outlined in the headlight painting in the DIY forum.