Avis Car Rental at 1670 Kettner Boulevard, San Diego, California.

Very friendly and efficient staff. Good place to rent and avoid airport rental surcharges.

Excellent Avis office, only 5 or 6 minutes from the airport and you save a lot of money not renting at the airport. Look into this option, plus if you are staying downtown you might just want to rent here a couple days later and enjoy the walking part of San Diego first.
Front desk offers excellent customer service, we were in and out for drop off and pick up with no problems and she even remembered us the next week and gave us 5 dollars off since tank was not full when we rented it. 5 dollars is not a big deal but it was nice that she remembered us the next week and did what she said she would do. We will be happy to use this location on our next trip.