Ive gone through this before and finally found something pretty perminent. Instead of once a month you have to do this about once a year or once evry other year. Get one of the kits that has the drill attachments and a light abrasive cream. It makes a world of difference. Here is the one I bought (the heavy duty kit).
http://www.autodetailingsolutions.co...tion%20kit.htm

 

I personally have found a lot of good results with the Meguiar's professional grade plastic cleaners and polishes... I use the following:

#17 - Meguiar's Mirror Glaze Clear Plastic Cleaner 8oz.
#10 - Meguiar's Mirror Glaze Clear Plastic Polish 8oz.

I also like to top it off with Zaino sealants (i.e. Z2Pro or ZCS). Hope this helps. I purchase from my friend's online shop:

http://pakshak.com/index.html

 

Get the headlight lens cleaner kit at AutoZone or equivalent and finish with PlasticX (or whatever it's called).

 

Like you mentioned in the OP, don't both polishing them unless you get the Lamin-X. They'll cloud over quickly. I took my headlights out, polished them with Meguiars plastic cleaner, then with plastic polish, and immediately put the Lamin-X on.

Been 5 months, no clouds.

 

I use PLASTX with good results that last 3-4 months, maybe more. A couple applications a yr and I'm good. I do garage the car at work and at home--so maybe that helps. A coat of wax goes on three times a yr on the paint and lenses too.

Not sure why everyone says 30 days is the max on PLASTX

 

I did mine a month and a half ago. 2 coats of wax and they still look fine

 

do the plastx after every wash and you will see them get better every time.

 

Anyone tried this stuff? Seems like it's probably snake oil but I've never heard good or bad online - google it and you'll just find a bunch of promotional "reviews" of it that say it's the best. Though the ebay reviewers who have bought the product say it worked. Hmmm....

 

ahh cant remember what i used but my friend offered me something and its super clear now

 

Has anyone used 2000 grit wet sand paper? I've always wondered how well, if at all, this would work. Works for clear coats and paint, why not plastic?

 

^ I read up that 2000 grit paper is OK to use but you must follow up with a hi-speed rotary buffer w/ rubbing compound to remove all those fine surface scratches and the cloudy residue from the paper.

 

good info guys! ill be taking this into consideration since my headlights seem to do this all the time -_-

 

I use PlastX, but the oxidation does come back in a few weeks. I just keep re cleaning the head light since it's only on my left one.

 

As a followup, I decided to be the guinea pig and try the stuff linked in my old post (quoted above). It didn't make a noticeable difference on my headlights.

 

Works like a charm. But to best remove the sanding marks, I'd recommend polishing with a PC or rotary.

I have used:

2000
2500
Menzerna SIP via rotary
Menzerna PO85rd via rotary
Zaino Z5pro x2

And ended up with what looked like new headlights on a customer car.