We were following a Harley Davidson motorcycle last week-end on our return 4th of July week trip. We were on secondary roads (not interstates) so no one could pass each other, so followed the motorcycle for a good half-hour through small towns and everything.
I noticed he gave a "motorcycle greeting" to on-coming motorcycles. It's the first finger pointed out with rest of the hand in a fist. Then the position of the arm is pointing toward the ground at about a 45 degree angle from the body .. left arm - hand! And I noticed on-coming cyclists doing the same back. That must be the new "thing" and maybe why it's not so noticeable as the old held left fist facing forward in the sky wave!
About RV-ers. Even though I am a former motorcyclist, I do not wave. Am I snobby? No... I'm watching the road! I see a gigantic moving house coming toward me, and I don't have the luxury to look the driver in the eye. I'm making sure I'm over far enough both of us can pass by each other without crashing or going off the road. On interstates, they are simply too far apart to see the driver in most cases. Either way, oncoming traffic to me are just big moving boxes I don't want to crash in to.