How to Clean Headlights?


08 CX-9 GT FWD
Nice, man! a word of caution to others - if you sand your lenses you remove the uv protective coating permanently and will have to continue re-sanding periodically. Or you can just keep your headlights clean all the time to avoid having them turn yellow.:)
Mazda CX-9 Grand Touring 2016
There are probably a hundred brands of headlight lens polishing kits. Also there are youtube videos of the polishing as well as wiping with acetone to remove the surface layer of the plastic.

First evaluate how bad your lens is. Pick a kit that will do the job. Very rough lenses need wet sandpapering before polishing. There are instructions available that show starting with 400 grit wet or dry sandpaper, then 600, then 2000 grit, then finish with polish. Or something like that.

Ultraviolet light causes the damage to the polycarbonate plastic lens. Garaging during days keeps them from clouding (how about finding a parking spot where the car faces north during days?). After renovating the lens, some UV protection extends the clear life of the lens. There are chemical UV protective coatings or clear plastic film PPF paint protection film. There are several brands, some offering kits. Here's one

Or hire a shop to renovate the lenses. Prices around.


Work In Progress..
'18 CX-9 Signature
I read you can use toothpaste.
Can confirm - rubbing toothpaste on the lenses with a terry cloth does work on light hazing, but it will come back fairly quickly.
2009 Mazda CX-9 GT
Update.... I polished my headlights back in July 2019 with a Surf City Garage kit. The past few months I've noticed them hazing over again, so today I gave them a good polish with the foam wheel from an old 3M kit, and some Mequiars plastic polish (both were laying around the house). They polished up really nice. I then put two coats of Mequiars car wax on them; will see if that helps keep them haze free for a bit longer that with no wax or anything.

Here is before and after:
2005 Mazda3
I've wrestled with headlamp restoration for years on my Mazda. The crucial thing is sealing the headlamp after polishing. Back in the day the only sealer they had was this product called blue magic(could've been genie?) and it sucked. I've experimented with many types of waxes, from Merzerna Power lock to Black Magic Full synthetic(discontinued but it was great stuff)... I feel like Merzerna had a hard time adhering onto the polished plastic because it only lasted about a month.

For the past 2 years I've used deck sealer.. helmsman polyurethane... it lasts about a year then begins to flake and peel... I think this time around I'm going to just keep applying Turtle wax seal n' shine every month so I don't have to keep sanding it down once a year. I've seen some others use nano ceramic sealant, but the good stuff costs about $75... which is more than I'm willing to pay for sealant right now.