Many people associate the car wave with Southern drivers - if you change lanes, you wave to the person that let you in. Well sometimes the wave is negated based on something else you do. 1. If you change lanes without signaling, and then wave at me, those two things negate each other. Turn on your signal...what am I, a mindreader? 2. The smoke wave. Sure, you've signaled, but you've got your hand out the window with a cigarette and now your smoke is in my A/C. If I'd wanted your cigarette smoke in my car, I'd have offered to carpool.