As expected, there was no Corvette. They were shocked at the confirmation I brought in, but showed that in the system is was booked as group A, which Boise does not even carry. They had a Subaru Outback a free upgrade, but I decided to keep my Avis rental.

Regarding T&C's on the Hertz website, this is what I found:

Disclaimers. WE PROVIDE THIS WEBSITE, THE SITE MATERIALS, AND ANY PRODUCT OR SERVICE OBTAINED THROUGH OR IN CONNECTION WITH THIS WEBSITE ON AN "AS IS" AND "AS AVAILABLE" BASIS WITHOUT REPRESENTATIONS OR WARRANTIES OF ANY KIND, EITHER EXPRESS OR IMPLIED, UNLESS OTHERWISE EXPRESSLY PROVIDED IN A WRITTEN, AGREEMENT WITH US TO WHICH YOU ARE A PARTY WITH REGARD TO A PARTICULAR PRODUCT OR SERVICE. TO THE FULLEST EXTENT PERMISSIBLE PURSUANT TO APPLICABLE LAW

Conflicts. In the event a conflict arises between any information posted on this website, this Agreement, and/or any contract you have with us, the terms of your contract with us will prevail over this Agreement and the information posted on this website, and this Agreement will prevail over information posted on this website.

An offering was made in the written confirmation I received. In many states, this is a binding contract which I could enforce. Of course I would be a fool to waste my time trying to remedy the breach of contract over seat time in a Corvette.