Did you know that when renting a car from Avis/Budget/Enterprise your spouse gets added as an additional driver for free?
I just rented a car with Enterprise, went down to change the reservation to my wife's name, they told me that it's automatic and free! I've never heard of such a thing. I just looked it up, and looks like there are many companies who have this policy, and that in CA it's against the law to charge at all for additional drivers.