You guys make me laugh.
I tend to wave to any one, except for scooters in cbd and st kilda. Also I wave to any road user who sees you and treats you like a legitament road user, not just a nusciance. Coz I grew up in the Hot Rod seen I tend to wave to anyone in, or on a cool set of wheels. Could be a GTR, Wrex, steetfighter, commuter, sporty or even a HD. Maybe coz most cage dwellers view us all as villans.
Of all the riders though, harleys are the worst. But that figures, a long time ago a wise old man tought me the second rule of hot roding; "if it dont go, chrome it!"
I,ve found the best wat fix those toooooo cooooool harleys is a mono at the first set lights, then just play with 'em at the next, and just smoke 'em at the third.
But be warned, I came accross one a couple of years ago that gave me trouble. On closer inspection it had a radiator, water jackets, and NOS, go figure. Still didn't stop too well though. But as it turned out, he was cool. We both laughed our heads off all the way to work that mornig.
To sum it up, Riders wave, and all the posers can please em selves.

It is far better to dare mighty things, to win glorious triumphs, even if chequered with failure, than to take rank with those who neither enjoy much nor suffer much, as they live in grey twilight that knows no victory nor defeat.