Below please find a few codes that matched or beat USAA's A177204 to give me the lowest rates I could find for several different weekend rentals at off-airport locations in the Austin, Texas area. With the exception of the USAA code - I didn’t find the below codes anywhere else in this forum or thread.

All discounts compared to standard weekend rate (without an AWD number)

gave me 15% off
B723712 International Alliance of Theatrical Stage Employees
B381920 Travelers Advantage
B021600 Wal-Mart edition Rand-McNally Atlas
A177204 USAA

Of the above codes - I feel that Wal-Mart's is probably the safest as it’s available to the general public. The other codes may require proof of affiliation such as a membership card.

gave me 20% off
K817625 Delta Airlines SkyMiles
Available to the general public - this appears to be a promotional AWD number - valid only until 31 Dec 06. It's also offering 250 SkyMiles per rental day for qualifying rentals of a minimum one day at participating Avis airport locations and up to 25% off standard weekend rates. Learn more at...
http://www.avis.com/AvisWeb/html/par...=aviscom_delta

Please reply with your experience with any of the above codes.