While pretty much a National fan (have mucho frequent renter credits), I lucked on a decent Hertz code early on -- that being the disboards code. But, wait, there is more, I poked around a bit and found a better Hertz code that I am fully qualified for and that dropped the price by another bunch of cash.
I don't mind mentioning the disboards code as it is posted at the top of the board, but, as much as I would like to share other codes, I have learned that the moment a good code gets mentioned on here, a percentage of "nervous nellies" call the car rental firm and quiz the rep about why such a good rate from said code.
Eventually, all those calls leads to getting the code killed....try googling the issue. You will see how that has pretty much killed code sharing across the web. Anyone with decent internet search skills can find the same codes I use. But, if you have those skills, odds are you know enough not to call the rental firms and ask why you got such a good price.
O.K., you say people who do not share are being mean...or not...but at any rate, I found the code...they are out there, they take a bit of work, but not really that much, seriously. But having a good code killed by people who are O/C about it is really "mean" in and of itself.
But, on a more serious note, prices are not moving very much this year, at least in my experience....