This is just an idea that worked for me, and still has to be checked out:
In the location near me, for some reason there was a $10 a weekend day rate. Combined with a PC number that was on the USAA site that gave you $10 off per weekend day - max $50, the total for the 5 day weekend (see below how to get a 5 day weekend) came out to $11 and change after tax!!! (The USAA PC code has expired, but you can still use the regular Hertz one 151034 and get $10 off a weekend day - max $40. Which is the same if your only renting till Monday instead of Tuesday.)
So what I did is... When I first saw the rate, I booked for the next ten weeks or so. Now that that rate is over, I called the location and changed the dates to a week that I hadn't booked for, or any week that wasn't available for this rate - like cratzmach weekend. Bottom line: I have a reservation for cratzmach and new years weekends - for $11!
So my suggestion is... If you can't get a good rate for the dates you need, book for other dates and then call the LOCATION and ask them to change it. When I called the national number, or tried online, they told me I couldn't do it since that rate wasn't available for those dates. For some reason they didn't notice this at the location.
Some other things that I used:
1)As was posted a few times in other threads, the best way to rent under 21 is with the USAA corporate. All you need is a SS, and it's perfectly legit - just sign up at USAA.com. They questioned it the first time, since we always use the Chabad corporate, and the guy at Hertz even called USAA but they confirmed that we were real members!
(For those that wonder how this can be legit if you are not in the military - if you read up about the USAA on their website, it says that it USED to only be for military members and their family's, but now only some of what they offer is exclusively for member and some is opened for the public - including their corporates and all of their shopping discounts.
2)Weekends officially start from noon on Thursday, but if you book your car for anytime later in the afternoon you can later go online and change your pickup time to the morning and you will still get the weekend rate.
3)The same thing applies for Tuesday, which is not really a weekend. I don't know if this will always work, but it worked for me... If you book your car for Monday and then go online and change the return date to Tuesday - you will get the weekend rate for Tuesday too.