Starting grid wheel wiggler here. I don't think I ever really do it on purpose—more as a nervous habit.
I'm bad on the WAY to the track. I get really bad butterflies about 5 minutes before I pull up to the raceway. It takes me a good 10 minutes of moving around once I get out of the car to shake it all off. After that, I'm fine for the rest of the day. Usually, my hands are shaking while I'm setting up my gear in the pits. I've been like that since I started racing in 1983.
Superstitions? Not really anything I do at the track. I have an odd ritual with the shower door squeegee every morning, but I'd prefer not to get into that...