I remember the motorcycle wave when I had my cbr f4, and like 986Jim wrote - it was typically from everyone on a bike, no matter what kind. You can tell that you belong to a select group when you're on your bike. It always makes me feel good when i get the wave from a rider, when I'm in my car and I move over in stopped traffic to let them pass (for those not familiar with California - motorcycle riders can 'split the lane' or pass in between two lanes of cars (technically in traffic moving less than 35 mph - although it happens even at speeds exceeding 75mph)
People who drive cars, though, whether it be Porsche, Corvette or Saturn, are a different breed
I think the problem with high end foreign cars is that, to a degree, people look at you and automatically categorize you into an assumed income class, based on which model you own/drive. Kind of like looking at someone in a WRX and thinking, cool car, but evolved-ricer punk? Or, a 325 and thinking - they got a good lease deal, vs the person in the m5 or 745 and thinking, hmmm, accomplished.