Used the Costco code for the 25% off and one additional driver for a Convertible on Maui (OGG). Our initial quoted rate for 1 Week plus 3 days...was $508 total.
I was re-pricing regularly and finally about 2 weeks prior to arrival that same code netted a lower rate for the same 10 days convertible of $405. So canceled the old reservation and rebooked a new one saving an additional hundred bucks.
So watch and reprice those rates often, as it seems Alamo discounts even deeper if they have excess inventory going into the final weeks. But don't wait too long or they could go up.
BTW...OGG Alamo never asked to see my Costco card.