Simply let valet attendants know when picking up and returning, and they will take care of the rest. The car is parked at a nearby airport parking lot with frequent shuttle service to/from the airport. Simply proceed to off-airport parking shuttle stop at the departures level. More information will be provided on the procedure after the booking is complete.
The car is parked very close to SFO airport at a nearby parking facility (open and staffed 24 hours), you will need to take a short and FREE shuttle ride (runs every 7 minutes) to the car from arrivals. Once in the parking lot, valet attendants will hand you the car.