Explainer Roadshow

How to clear up your headlights

Cooley tries seven ways and the winner surprises him

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Most cars on the road today have a plastic headlight assembly that can yellow with age. UV radiation from the sun turns the crystal clear housing into a hazy, cloudy thing that reduces overall brightness, blunts the beam pattern the manufacturer so meticulously engineered, and just makes your car look like beater. 

We brought in a 1990 Lexus LS with typically cloudy headlights and attacked them seven ways, ranging from specialized headlight products to home brew remedies that are all over YouTube.

The Worst

Surprisingly, the dedicated product from Rustoleum was the last satisfying. Its name and marketing rubric suggest a simple wipe-on process, but as soon as you open the box you find a two-stage sanding block. Once you finish sanding and then wipe on the special clearing chemical, you are directed to let the car sit for 24 hours away from moisture and dust. That's not at all what I equate with "Crystal clear headlights in just seconds."

The Best

To my surprise, Meguiar's PlastX hit the sweet spot of easy use and clear results. We applied it with a buffing pad on an electric drill running at 1,250 RPM and moderate pressure. That's it. No sanding, no multiple steps, yet it left our headlights looking like new and two weeks later they still looked as good. I didn't expect something so easy and that isn't even marketed as a dedicated headlight solution would really work that well. 

Insider Secrets

Ideally, you won't find yourself needing to do this at all so keep these tips in mind:

  • UV radiation from the sun seems to be the main culprit in headlight hazing. Park your car indoors or, if that's not possible, at least park with the front end under shade.
  • Replacing the headlight assembly on many cars is very easy. (On many late model Porsches its much easier than changing the oil.) If your headlights are really bad consider replacing them with a clean used set off eBay for the local junkyard.
  • Know that when you polish your headlights as we've done, you may be removing an original surface protective coating, but clearly it failed or you wouldn't have done this in the first place.