Polishing headlights

[RawSouth]

Ive used Maguires plastic polish on my 8B...

It seems to work pretty well, but I have to redo it every few months (its not too bad, it reminds me to put some more RainX on too )

[Hammer]

x2 on the Maguires stuff.

Also check this link. The entire process is not about polishing, but parts of it is. It might give you some hints and tips.

[Alex]

yea depends how bad it is, if it's just haze then polish should work fine, if it's got a cracked surface as well then sandpaper will be required.

[Mr Morlock]

This subject has been raised a number of times. The lenses are moulded from polycarbonate (PC) and are hardcoated and the Japanese usually spray the hardcoat. The purpose of the hard coat is durability- without the coat the lenses deteriorate very fast and will crack and fail. To restore the lenses any gentle auto polish will be quite effective unless they are already in a very poor state. The Meguiars product will work.
I shudder at using Brasso - it is a ancient metal polish and not designed for plastic. PC can have reactions to some products ie like stress cracking. Wet and dry is a definite no no - it will remove too much of the hard coat and shorten the life of the unreplaceable lense. Look around at various cars and see lenses which are milky to see what happens without a little care.
Incidentally taillight lenses and repeaters are moulded from acrylic ( pmma) and these are not hard coated and the reason is that pmma has excellent durability though no where near the impact strength of polycarbonate. Each material in the car is selected by the engineers for a specific purpose.

[Alex]

if you've got to the stage that the lights are very cloudy then any coatings are already broken down.
Wet and dry is the most effective way to get rid of the small surface cracks that appear on the top layer, or you could spend hours trying to polish it out.

[Mr Morlock]

you can only provide advice hopefully based on some experience. Wet and dry is wrong for plastic headlamps- you do not want to remove the hard coat merely "polish" it. I never cease to be amazed at people using the wrong products without doing any research. Examples are like using brake fluid to remove paint. Many plastics are adversely effected by some cleaners and you may find out only after making the wrong choice- best to read labels. Brasso has been around for probably 50 years maybe more and many materials have changed in that time so I use it for brass.

[DaveWA]

work your way from fine to super fine wet and dry paper, leave the wet and dry paper in water(in a bucket/container)