I have an upcoming trip to SFO and was wondering if you California experts could clear up some conflicting information for me. In digging through the archives on some other travel sites, I have found some vague information suggesting that rental car companies are not permitted to charge additional driver fees in California. However I cannot find any recent information to confirm this, nor can I find any such language in the T&C's on any of the rental car companies' web sites (except for Fox which seems to exclude California from the list of states they charge additional fees in).

I've never had to pay additional driver fees in CA in the past, but the additional driver has always been a family member. In this case, there will be three non-related persons driving the car.

Anyone have some insight on this?