MAGLIOZZI

Dear Car Talk: Do any of the self-service products for cleaning front plastic headlight covers really work well, or is the professional service the only good choice? — Don

Yes, they can work. I’d say having it done professionally is often better. And replacing the headlight lens is best of all.

What happens is that, over time, the polycarbonate coating on your headlight lens wears out and the lens gets cloudy and yellow.

That eventually “filters” your headlights and limits how much light gets out onto the road in front of you.

Repairing these cloudy lenses is a two-part process. The first step is sanding off the old, worn-out coating. Do-it-yourself kits have you use an electric drill, spinning a piece of sandpaper until the lens is perfectly clear again.

Once it’s 100% clear, you apply a new coating to the lens to protect it from turning yellow and cloudy again. And the lenses come out much clearer. And do improve the headlight performance at night.

When we do it at the shop, we have better sanding equipment, we’ve done hundreds of them, so we know when we’ve sanded enough, and most of our guys remember to tape around the headlight, so we rarely sand off customers’ paint anymore — at least on the newer cars. There’s probably also a difference in the quality of the replacement coating from kit to kit, but I can’t really speak to that.

The repair doesn’t last forever. The more exposure your lenses have to the sun, the faster that protective coat will wear down again. So, it’s not a perfect nor a permanent solution.

What is? Replacing the actual headlight lens. But that’s expensive, which is why a lot of people opt for these kits.

A middle ground is to ask your mechanic or a local body shop to do it for you. At least that way, if they sand off your paint, you’ll already be at the body shop, Don.

Got a question about cars? Write to Ray in care of King Features, 300 W. 57th St., 41st Floor, New York, NY 10019, or email by visiting the Car Talk website at www.cartalk.com.