Nice Offer starts on January 8th and is good for weekends at $10 per day +++. Thursday 9AM starts the weekend and must drop off by Monday.
Here is the link
I guess $36.66 total for three days solves my car rental problem in San Diego 
We took the mid-size but larger cars were available for the same price.
And here are the terms and conditions:
Valid at participating US locations from 1/8/09 through 5/31/09 for rentals of an economy through premium size cars. 24-hour advance reservation required. Minimum one day/maximum four day rental required. Non-participating locations include, but are not limited to Denver, Aspen and the New York Metro area. Cannot be combined with any other discounts or promotional rates. Availability is limited and blackout dates may apply. Weekend rate available 9:00 AM Thursday; vehicle must be returned by pick up time on Monday or higher daily rates apply. Rental must include a Saturday overnight stay. Taxes, other governmentally-authorized or imposed surcharges, vehicle license recoupment fees, airport and airport facility fees (of up to US $4.50 per day or US $15 per rental), fuel, additional driver fee, one-way rental charge and optional items (such as CDW Waiver Savers® up to $29.99 per day) are extra. Check your insurance policy and/or credit card for rental vehicle coverage. Concession recoupment fees of up to 12% may be added to the rental rate at some on-airport locations. Up to 11.11% may be added to the rental rate if you rent at an off-airport location and exit on our shuttle bus. Other surcharges and recoupment fees may apply. Renter must meet standard age, drive and credit requirements. Rates may be higher for drivers under age 25.
