Ive been driving an old bmw m3 for quite some time, and my brother drives a 2003 m3 as well, and i can tell you that almost any fellow m3 driver will flash eachother the brights and wave as they pass one another. I would hope its the same with the V, although it would be more rare to see another V.
I think it's universal from motorcycles, cars, boats, etc. When another similar vehicle is right next to you there is usually a little nod, tip of the cap, or wave to say, "nice choice friend". It happened with my Volvo, Audi, and I hope so with the V. I haven't seen another one yet though. I did get a couple of nods from 3 vette drivers so far.
There are lots of Vs here in the Dallas area. Unfortunately it seems that the new crowd in the V2s dont recognize the V1s. I've seen a a few V2s on the road and have yet to have one of them wave back (Except of course for forum members CadV, Silver-V- and Fubar). V1s are another story, 99% of the time will initiate or respond to a friendly wave.
When I drive my fiance's JK 4 door Wrangler I get waves all the time.
Corvette News promoted waving at other vette drivers, 40+ years ago. Don't know if waving started with the vette, or with motorcycles, but half the time when I'm in a vette I don't get a wave back from most new vette owners. Older vette owners seem to wave more prolifically.
As for the CTS-V - I've had mine 10 weeks, and the next V I see on the road will be the first one - besides my own. I'll wave, and he/she won't know why I'm trying to be friendly.