You're leaving the Fairmont to go of for a week, but are you then returning the car directly to SFO, or to somewhere in SF and then heading to the airport at a later date?
Either way Palo and and San Rafael are quite a ways from SF and the bus fare and time spent getting there would make it not worth it IMHO.


If you're returning the car directly to SFO, I would take BART to SFO and then as all the rent a car booths are at a central location, it wouldn't matter which one you used.


If you are going form SF to SF proper, I'd use the Union Sq or O Farrell St locations.