I got a kick out of that. Enough, that I just did the hand gesture myself..Funny, but good, idea.
Here we just flash our high beams.
I was riding around one night and was the only one in the car not smoking pot. I kept telling them there were always roadblocks on the road we were on but they didn't listen. A car comes around the curve flashing their brights and saved our ***..Come to find out, there was a road block..whew...