I just got a Midsize through Priceline and Hertz for $12/day for 9/11-9/22; comes out to $231 including fees/taxes. Here's how I did it:
I bid $10 for a Compact and it didn't get accepted. Then I bid $10 for an Economy and won that. It then let me upgrade to Midsize for $2.00/day. HTH. Too tired of waiting on Alamo rates to come out. You used to be able to get Mastercard discounts or AP discounts a lot earlier. Now they don't seem to effect the rate until it is really close to vacation. I can't stand having that just hanging. So to recap, I got a Midsize for 11 days and 23 hours for $231 including all fees 55 days out.
Good luck everyone!