Foggy or dull headlights can become a major safety issue when you're driving in inclement weather, so it's in your best interest to keep your vehicle's headlights clear and clean. Most car headlights today use quartz-halogen bulbs attached to large plastic reflectors. The bulbs are protected by an outer surface of molded polycarbonate plastic, which has a tendency to become oxidized over time, causing it to fade and become discolored. This steady degradation eventually leads to a dull state on the polycarbonate cover, which cuts down your lights' ability to cut through the night.
Lay down some low-tack painter's masking tape around the edges of the clear plastic headlight cover to protect the headlight assembly from scratches as you begin sanding.
Wipe down the outsides of your auto's headlights with a polishing compound and a microfiber cloth. Use a circular motion when doing this.
Dampen a piece of medium-grit sandpaper in a bucket of cold water for at least 10 minutes and begin sanding in a side-to-side motion. Wipe the lens off in between sanding. This time grab a higher-grit sandpaper and start sanding again, only this time more deliberately. You may have to repeat this process several more times before you start seeing results.
Wipe down the lens with a dry cloth. Check the lens for any hairline scratches, before removing the masking tape and reattaching the lens. Use an electric buffer to remove any scratches you come across. Finally, apply a coat of wax on your lens.
