Weed eater has it right, Bay Area drivers are friggin INSANE! I'm not sure if they feel like they are priviledged and blessed by a holy power to do whatever they like (usually driving way over the speed limit in urban areas or general dangerous nonsense) but they will do whatever they want. You have to expect the unexpected. Last year I was seriously injured by a vehicle turning right from a left lane and breaking me up pretty bad off a motorcycle.
If you ask me, it's like a third-world country on the streets here. Go to a nice neighborhood and people act friendly in foot. But get behind the wheel of a car and they're trying to get you to hit their car, or trying to hit your car, perhaps trying to get money out of you. It makes no sense to me.
On a happier note I got a new bike today and rode for over two hours without one honk, curse, or close calls from motor vehicle drivers. Big thumbs up to that!!