I think they rely on the fact that at some airports in particular you can celebrate your next birthday waiting in line to get your already paid for rental car. We sign on the lines that they tell us to. We’re so frustrated and behind schedule that we initial, etc. without reading. Then when you turn the car in they include additional charges for you sign and get on the shuttle, I didn’t find the additional charges until I got my credit card bill. I tried to talk to the folks in LA, to no avail, I tried to talk tot he folks at the Thrifty car home office to no avail. They have proof that you approved the additional charges, which you/we did under false pretense. I tried the better business bureau in LA to no avail.
The take away is to not rent from Thrifty ever again. I have not and it’s been 11 years and hundreds of rental cars later.