When I bought my car I had no idea that I would be expected to wave to every other Mini owner as I pass them. It would be one thing if most drivers just didn't do it but they do. Easily 90% of the Mini drivers I pass do some variety of the wave. Most tend to stick to the two finger variation of the Cub Scout salute; some just a casual "I'm almost too cool to do this" wave without taking the hand from the steering wheel; some actually use the "hang loose" surfer wave, and once I even got the heavy metal devil horns.
Back when there were only a few Minis on the road this might have been fun, but the truth is that there are tons on road. They're everywhere. I love looking at the different models and how people customize theirs, the different color and stripe combinations. To me it's a really aesthetically pleasing vehicle. I also love driving mine; it's the most fun I've ever had driving, and I guess other Mini drivers love that aspect of the car as well.
So, aesthetic appreciation and the assumed love of driving a handley little car suggests that Mini drivers have so much in common that we should wave to each other as if we're all casual friends? Am I just a curmudgeon? Maybe, but I'm only going to wave when trapped. Once I've made eye contact or if I'm stuck across from another one at a red light, that's trapped and I'll wave then.