I'm a wave initiator. I'm the obnoxious one honking and arms out waving at people. So they wave back. Yesterday, I want to say it was on Henderson Rd in Clifton, black Cooper S with white stripes down the middle, she waved. Then a little later, saw a silver cabrio with black bonnet stripes and top up, no wave. And mind you, yesterday was gorgeous. I was very fussy that they had their top up.
Monday, I drove up Hoadly Rd in Manassas, got waves from both MINIs I saw - one was a blue Countryman, the other sad a Clubman.