I still use the headlight flash for the cop signal. I don't know how many people now days get it but I do it anyway. Seems like it's been a long time since I saw it coming back my way. But then, I don't get out as much as I used to either. As far as waving, I wave. Never heard of the top of the helmet thing either. I think the Gold Wing guys only wave at each other. When I had a Gold Wing they waved to me, but now, seldom do they wave, even if you wave first. I have found most H-D guys will wave to most other bikes. The sport bike guys don't seem real big on waving. But if I had to average it out, I would say if I wave to a bike, 75% of the time I get a return wave. If someone waves to me I always wave back.