CARS.COM — Driving home one night, I pulled onto the highway on a dark but clear evening behind an older Jaguar XJ sedan and was blinded by the driver’s fog lights, even though there wasn’t a bit of fog that evening. How could I tell that his fog lights were on from behind the car? Because, like so many Americans, this driver didn’t seem to understand what the fog light switch does in his fancy European luxury vehicle: Sometimes, the switch for the fog lights turns on a light in the rear.
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In a number of high-end European cars, the fog light button not only illuminates additional driving lights in the front bumper, it also brightens part of the taillights so that your car is more visible to vehicles behind you in the fog. These fog lights are especially useful on Europe’s high-speed highways, but also in any situation of decreased visibility, like snowstorms, thick fog, heavy rain, etc. What this looks like varies from one model to another. In some vehicles, it looks like the driver has their foot on the brake. In others, it might just be a small but brilliantly lit bulb in a larger taillight assembly. Rear fog lights are not common in the U.S., but since they are present on some high-end vehicles, it’s important to understand them.