Basically, I ordered an intermediate size car (Dodge Avenger or similar) and was given a Chevy Cruze. A Dodge Avenger is classified as a mid-size car by Dodge and the Chevy Cruze is classified as a compact size dar by Chevy. If I had wanted a compact car I would have rented a compact car and paid somewhat less. But no I wanted something larger and ordered a Dodge Avenger equivalent.
I called customer service to complain about the vehicle size and they explained that they are classified into the same size even though they are not. They were not at all apologetic and were 100% unwilling to help me get a replacement vehicle.
In the end I paid Budget extra to screw me over and give a compact car for more money because of Budget's "creative" vehicle classification system.