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no, hadn't really thought about it in too much detail but if had to come up with a theory I would have said that they detect the movement of the car and so if you flash your lights it seems like the car is closer. Or something like that. Anyway, what I'm studying at uni has nothing or at least, very little, to do with how sensors work so even if i had no thoughts on it at all it wouldnt really have an influence on the fact that im at uni in the first place.