I haven't seen any Corvette Stingrays at SFO, and I think they only do the Corvette Z06 100th Anniversary Special now.
Also I confirmed with Hertz that they don't carry Camaro SS convertibles at SFO (and prly not at other west coast airports i.e. LAX either), and don't plan to do so. I guess Hawaii gets them because the vacationer market demands them? Oh well