2x this week got the wave. One from a guy in a really really old stripped down Jeep and the other a wave and a story from an old timer in a Buick Centery (he bought a Jeep in 1945 that came in a box. A real put together story shared at a red light). My experience:
LR owners do not wave back, RR owners talk on the phone, I do not see FreeLanders on this coast, Defender owners wave a lot
Jeep owners who are old do the wave, Jeep owners who are young do not. Owners of classic Jeeps will stop and chat (I saw a 1943 Navy Jeep last week which was really cool)
Raised trucks (unless 3' plus in the sky) do the wave, Desert kitted trucks do not.
The wave is for people who care n share. Save the wave for the caring but share non-the-less