One yellowed headlight on a car from Japan: what it can mean

Headlight lenses go yellow over time, mostly because sunlight breaks down the protective coating on the plastic. When only one is yellowed, it's worth asking why, and there's more than one possible answer.

Why only one side, in my view

There are a few reasons. Two I'd point to:

• The sun hits one side. My own car is parked where the sun comes from one side, so one headlight can't help going yellow. On our sample report, the right headlight on my car is yellowed and the left one isn't.
• One headlight has been replaced. The more common reason, in my view, is that the car was in an accident and only one headlight was replaced with a new one. The new one stays clear; the old one has yellowed.

So a single clear headlight next to a yellowed one can be a clue that the front of the car has been hit. It isn't proof. It could be the sun, or a lamp replaced for some other reason. We don't certify accident or repair history, and we don't decide what a clue means for a particular car.

What a photo can and can't show

A listing photo can show that one lens is clearer than the other, if it's taken straight on and in good light. It can't show why. Strong light and reflections can also make a lens look clearer or hazier than it is.

What can help is looking at the front of the car around that headlight: the panel gaps, the paint and the bolt heads. See how to tell if a car has been repainted, and for what a Japanese listing's "repair history" line covers, repair history and flood cars.

The windscreen

A cracked windscreen is one thing you probably won't see on a car for sale. In my view, a dealer will usually have it fixed before putting the car out on display.

What we can't tell you

• Why one headlight is clearer. We photograph both, side by side, and mark the reason as something the dealer told us, or as not known.
• Whether a car has been in an accident. We photograph the signs we can see. We don't say a car has, or hasn't, been in one.

We don't tell you whether to buy.

Spotted one clear headlight and one yellowed one in a listing? Send it to us and tell us to look at the front of the car.

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Asking the dealer

You can ask the dealer whether a headlight has been replaced, and why. Whatever they say is their answer, and we mark it as Reported, not as something we've seen. A Remote Check is where we put that question to the dealer in Japanese for you.

Written by Yoshiaki Sagara, a paintless dent repair and detailing technician in Japan. He looks at cars for overseas buyers through Ninja Desk Japan. About us

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