I don't want the Dave-ish advice cuz, no duh, I could get a credit card and do it that way. I don't want to.

So question is, I can rent a car no problem online with the rental car companies. I unfreeze my credit temporarily so they can run the check and all good. Only thing that I've run into is that they only let you get the base tier vehicle. My wife and I wanted a 4x4 when we went to Colorado for Christmas and wanted a convertible when we went to Key West for the honeymoon. However, both times we were able to pay for that vehicle on the website, with a debit card, only for the rental location to tell us we can't have that tier car. When in Colorado for Christmas, we ended up in a Camry and got stuck in the snow once.. Has anyone found a way around this?