many thanks to this forum...

I tried a ton of combos for a 4x4 today, and used a BCD that USAA gave me on their site:
BCD Y126511
together with
coupon #MUGZ009
$170-$30 = $140 for 5 days 4x4 in Northern California

AMAZING deal, it wound up being $60 less for a 5 day rental than the Costco BCD above.

I am a USAA member, but I don't see how they can verify @ the counter as we aren't given any member card etc.

I only need the car for 4 days, but for whatever reason renting it for 5 days versus 4 was much cheaper, as it probably switched to a weekly rate.