In my experience renting cars, many car companies buy specially stripped cars that you can not get at a dealer.
For example, when I was in phoenix, we were assigned a new dodge neon “fleet” edition. The manual inside the car even said fleet on it.
This thing had no option but air conditioning, not even cruise control.
Same deal with the taurus last year, you couldn’t buy a taurus at the dealer, but the rental car companies bought them all up.
The nicest rental car I’ve ever had was a free upgrade, when enterprise gave me a 06 dakota 4x4 club cab instead of the marshmallow that geico provided.