Here's a link that describes Herbie's car and how he came to purchase it.
Just A Car Guy : Herbie Hancock
I like the part where he talks about buying a Ferrari and putting the Cobra into storage and he talks to the Cobra, which had been his daily driver and says "This is for your own good; you’re too valuable to drive. Look, I’m replacing you with a Ferrari; at least it’s not a Chevy!”