I've bought myself a 2001 CL Type-S; its a high-milage car in surprisingly good condition for both its age and its milage. Ten years of sun, stones, and polluted air have left the headlight lenses in just the condition you are immagining; dirty, scratched, and dull. I think there is some moisture on the insides too.

I thought I'd just run up to the local big box Auto Parts store and pick up one of those lense restoration kits. You know the ones, some kind of soap, some kind of compound, a little buffer and maybe some wax. But then I though better of it.

I do some custom painting on motorcycles but its way more a hobby than it is a job; I paint three or four bikes a year. When you finish a paint job you "cut and buff" it. That means it is sanded with progressively finer sandpapers and then buffed to a perfect finish using several different compounds and buffing pads. So I have quite a bit of sandpaper in the right grits to finish a surface (I keep everything from 240p-2500p here).

So I'm thinking about the headlight lenses and I can't think of any good reason why I couldn't just use what I've got to refinish the things. I thought I'd clean them and then sand with 800p~2000p grit and then try 3M Perfect-It II on them and maybe finish with a swirl remover. The one thing that I'm concerned about is the heat generated by my buffer. With paint you need a certain amount of heat to push the paint around but I'm concerned that using the buffer (7" Makita 9227c) even on a low speed might harm the plastic.

Anyone got any experience cleaning up the lenses mechanically that you'd care to share, particularly if you've tried using a big buffer on them?

 

I used Maguires clear plastic cleaner with my buffer. It worked acceptably well but I ran out of buffer pads (3). I had a friend use his buffer with a marine grade compound and it worked awesome...

 

Just tape off the bumpers and fender where they meet the headlight and go for it. The heat wont do anything. I used Meguiars Plast-x to polish mine after wet sanding.

 

x2, you pretty much hit the nail on the head with the process- that's all those "kits" really are anyway. I would also recommend plasti-x as a last step. One thing however, you should protect the headlight with a quality sealant a bunch of times throughout the year as you'll be getting rid of the factory UV protective finish by polishing the lense via your rotary. By doing this you'll prevent the problem from happening again.

 

My lack of experience showed when I tried it. I got that paste all over everything. All in the engine bay, fenders, me, bumper, everywhere. Took a long time to clean up.
I got fed up & just replaced the headlight completely.

 

x2, definitely seal the headlights every month or so.

If you are up to it, there are UV resistant clear coats on the market that you can use on the headlights as well to keep them clear. Id still apply a sealant over that though for a bit of extra protection.