Around my area it's more of a "lifted vehicle wave".... basically i give props to ANY modified/lifted vehicle regardless of make/model, and always get a nod in return.

I never really understood the "Jeep" wave... hard to explain... but it seems too much like blind brand loyalty (ya know... those people who own a Jeep just for the sake of having a Jeep). I'll wave to a modded to hell 4 runner with mud tires and a snorkel before i wave to a grocery getter stock wrangler (not that stock wranglers aren't capable... just trying to make a point).

When i had my silverado lifted on 37s ill never forget the time that i was turning through an intersection and got a giant "thumbs up" from a lifted F250 super duty. Yes, i returned the favor... it's always nice to know there are still guys out there who respect the "sport", not the "brand".

Edit: FWIW, i DO the motorcycle wave as well... don't care if you're on a cruiser or sport bike. But i do know guys who won't wave to another bike unless it's a Harley; that crap reminds me of the "jeep" wave (might be a better analogy)