Lane discipline is in its infancy in the US, they'll drive at any speed, in any lane, it can be very frustrating though there are signs appearing to keep right unless passing. US not as anal as the French re all the extras you need to carry. Check the car over, even if you're exhausted after the flight and get everything noted down. If you're staying in SF, don't bother with a car, it's hard and expensive to park, collect it when you're ready to move on. Go North of SF, it's glorious, especially at this time of the year.