Blue pill for Rentals ! You would've covered all terminals and airport facilities (if flying Delta) to get to car rentals. Plan for additional 10 mins just for transfer
If you have checked luggage & u happen to have 2+ people & getting a rental car - send one person to get car & bring back to pick luggage & people. As slow as baggage claim here is, it will save time
Using the AirTrain to get to your rental a car? You are paying a $20 fee (on your rental car contract) to fund the whole AirTrain system. You're welcome SFO.
For those frequent car renters - head to back of train to catch escallator to rental program ( hertz and avis ) preferred floors withou navigating the backlog of non prefer ed renters.