That's a good question. I hit the button and I see the fog light indicator on the dash go on but I can't tell the difference.
There's a different switch for that feature and I've tested it. If you turn the light switch all the way to the left then the driver side rear "parking" light comes on. Turn it one click to the right and the passenger side rear light comes on. This is independent of the fog light. I'm guessing you didn't get your CLA yet.2. on my older w140 I remember there was an option when you park the car on the side of the street you can put your turn signal "on" as in it's left like you're going to turn right or left, and when the car is off a light will light up on the rear of your car, this is for when cars are parked in narrow streets in Europe and at night to keep people driving by from hitting your car, I don't know if this feature is on newer cars though
I drive I-80 every day to and from work but in NJ but I know about I-80 in PA. I just don't see how that little red light in the driver side tail light is very visible by anyone in the fog. Maybe I'm wrong.If you have ever been on I-80 in NE Pennsylvania in the fog or have seen the 20 and 30 car pile ups that occur in areas of dense fog, you would appreciate having the rear fog light.
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