[braythwayt]

The fellow is parking the car in his own garage, and ZipCar claims to be in the car business, and it is normal to park cars in garages.

I say they have tuna salad on the menu, but they apparently can't always serve it to everyone.

Your suggestion that he order something else to eat is like telling a ZipCar customer to move to a different condominium or whatever.

They don't "have" to do anything, provided they aren't discriminating against him on the basis of a prohibited factor like race or gender. Just as a restaurant doesn't have to serve you (subject to the same caveat).

But the important thing here to note is that the hypothetical restaurant has organized their business in such a way that some customers cannot get what they claim to serve, just as ZipCar has organized their business such that some customers cannot enjoy the service they claim to offer.

They don't have to do anything, but I object to blaming the customer for their choice to run their business in such a way that a very ordinary thing that some customers can do, others cannot.