[M_Six]

Before automatic headlights, you could just switch your lights off and on to warn someone about driving without lights. But with any car I've had with automatic headlights, it's hard to do that because the lights don't turn off right away when you go to the off position and by the time they do, the oncoming car is gone. I usually just flash my high beams these days. The folks driving w/o headlights are often too clueless to know what you're flashing about anyway. Or it's a case of "I can still see where I'm going without my headlights." They don't understand that it's all about other drivers seeing them.