Cloudy headlights affect thousands of vehicles in virtually every make of car and truck, foreign or domestic. Headlight restoration or headlight repair is the procedure of cleaning the headlight lens with headlight cleaner kits or with items sometimes found at your local auto parts store. Save money over expensive replacements, restore them yourself, it’s simple and fast, additionally anyone can do it with no special training or tools.
If the headlight lens has light discoloration with no apparent scratches you can look at a solvent like napthalene which works quite well on headlights, start with the 2500-grit sandpaper. If the contamination is pretty severe, start with a rougher grit like 400. Typically you should have heavy/severe discoloration with apparent scratches/imperfections requiring a (rougher) grit sandpaper like the 600-grit. The higher the number, the finer the grit: 600 Roughest=>1200=>2000=>2500 Finest Eyeglass Lens Wipes B08BZR42KL
The first sanding step is to will actually remove the “bad layer” of plastic. The other grades of sandpaper are to remove the scratches left from the previous grit so your sanding time decreases as you come up in grit. (Remember 600=>1200=>2000=>2500)
Once sanding has begun you will soon see milky drippings as you sand—this is the goo you would like to remove. Keep sanding until the surface feels really smooth & the drippings become more clear. Grab the next grit sandpaper, in this example it will be the 1200-grit then repeat the same process and again for the 2000 and finally the 2500-grit sandpaper. You ought to do headlight restoration in the shade, not in direct sunlight. Lift the hood of the car in order to have full access up of the headlight lens for cleaning / restoring.
Always evaluate headlight lens for any moisture or cracked parts. If there’s any moisture trapped inside the lens, this means there exists a leak somewhere in the headlight assembly and cleaning the outside of the lens will only minimally improve the appearance and light output. The inside of the headlight lens has to be cleaned, dried and then sealed to prevent further moisture from entering. It’s also possible to remove excess moisture by drilling a hole in the lens to let the moisture out and then reseal with a rubber plug or silicone sealer.