Hmm, that's odd. I was always told that flashing your lights was aggressive, and blacking them out was passive. For instance, if I'm driving and someone wants to turn in front of me (lane change, or entering roadway), and it's unsafe, I will flash my high beams to tell them 'no'. But, if someone needs to get over, and it's safe to pass (like a truck changing lanes to get to an off ramp, etc...) I've always killed my lights to let them know there clear to move. This also applies to a courtesy acknowlegement. If I'm going down the highway and for instance a truck changes lanes to let me pass, I'll flash my clearance lights off as a sign of thanks. And I've recieved the same when I've let trucks over. I guess it's just differant all over... -Robert vin 6585 "X"