BMG: Z619843 (25)
USAA: Y126511 (21)
Costco: W852873 (25)
I found the Costco code to be pretty good for the dates i was checking. But of course there is no rule
Coupon Codes
(There are way more out there I just personally found these to be most helpful)
$10 MUWZ164Free weekend day TUFZ015 or TUGZ022
20$ off min 4 day rental MUWZ166Upgrade UUCZ002$35 Off weekly Rental MUGZ165