Always nice when 'classic car' drivers greet each other as they pass on the roads, part of our social fabric in a way.
Similarly I always like greeting and being greeted by fellow motorcycle riders. Although not all Harley riders will greet non-Harley riders, most do and I always do from my non-Harley ride.
Reminds me of how SAAB drivers in the seventies would always greet each other on the roads in The Netherlands. Probably no longer, although perhaps as they get rarer and older, we can revert back to EeVeeWee's approach!