At SFO I rode the train out, once stood in line for 45 minutes to get a car, went down and found the car in the space wasn't the car I was supposed to get (and the key didn't work), waited in line another 45 minutes, then got in the car to find out that it wanted an oil change, got a cell phone call from the police because my wife (who threw up twice on the plane) didn't know what happened to me, and then I remembered that I forgot to get a child seat in all the confusion for my two year old.
I drove the car perhaps 1000 miles in the next week, down to San Luis Obispo and out to the Sierra Nevada and around the Central Coast region. I never changed the oil (I was too traumatized to want to call Hertz.) This is why you don't want to buy a used rental car. On the way back we had some trouble with the brakes but we got back alive.
At LAX on the other hand, I got a ride on a shuttle bus to Hertz, spent about 5 minutes in line and drove out with a decent car.
(The mistake we made there was thinking we could drive north on the 405 at 5pm on a Friday, I really should have driven up La Cienga, but I can't blame Hertz for that.)