I had a similar talk with a colleague here at work.
He bought a brand new Mazda 3 about 18 months ago, and one of the nice features of the entertainment system was the built in Pandora support.
Now that Pandora is no longer available in NZ he must be able to get a replacement car surely?! :)
The difference here is that Pandora is a third party / external service. It has nothing to do with the functioning of the entertainment system - other than integration with an external provider. So no, no new car expected under this circumstance. However, if integration with Pandora was such that the entertainment system no longer functioned then I would argue that the software would need to be patched so that it is functional.
I don't believe this to be the same thing as having to switch off a feature of the device in order for the device to be secure.
Except that if you had told the sales person that Pandora was the reason you were buying that car, and they said yes this car has Pandora, and now that feature no longer exists, then what?