Most late-model automotive headlights are actually replaceable bulbs mounted in assemblies that have clear plastic protective shields. Over time, acid rain, salt and dirt residue form a yellow haze over the surface of such headlight covers. Yellow haze on headlight covers reduces the headlight beams' brightness, reducing visibility at night. Instead of spending a lot of money to replace your headlight covers, you can clean the covers yourself and save time and money. Using the right cleaning methods helps penetrate and remove the haze, making old headlight covers appear clear and brand new.
Tape all the way around each headlight, using 1.5-inch blue painters tape. Secure the tape by rubbing your fingers over it.
Clean each headlight cover, using a rag, to rid the covers of dirt, sand and residue. Sand and other small abrasives can scratch the headlights during the cleaning process.
Dampen a microfiber cloth with polishing compound and begin polishing the headlight covers, without passing over the tape onto the car finish. Carefully polish each headlight cover in a circular motion until the surface appears dry.
Inspect each headlight. Look for leftover haze and residue. If the headlights still appear yellow and hazy, you must complete additional cleaning.
Wet-sand each headlight cover, using a wet piece of 1000-grit sandpaper. Carefully sand the surface within the tape protection. Apply light pressure while sanding and sand in even, straight lines to avoid leaving deep scratch marks. It's helpful to direct a flow of water from a hose onto the headlight covers as you sand them.
Wipe off the headlight covers, using a clean rag. Check to see if the yellow haze remains on the surface. If the headlights require further cleaning, switch over to 1500-grit sandpaper. Continue the sanding process until the haze has completely lifted off the headlight covers.
Polish each headlight again to remove scratches caused by the sandpaper, followed by a coat of wax. The wax protects your headlight covers from future yellow haze staining.