It is illegal to flash the lights? I do not understand
Some particularly creepy individuals run around with flashing red lights that they pop up on their dash so they can get women to stop on lonely roads at night.
Although we haven't had much of that lately,it seems to be one of those strange little folkways of the Mid-Atlantic states.
I've lived around here since the 60s and seen enough of this stuff go on to believe that it's worth regulating the practice.