If they really don't include a modem as they claim, then it would be truly fundamentally different, and apple's privacy claims would not be an apt comparison.
If a user does not install the Slate app, there would be literally no way for the vehicle to collect any information whatsoever, it would be like driving an EV from the 90's, if they had better batteries back then. That would make it stand out as the only privacy respecting modern production vehicle I'm aware of, besides toys for the rich like a Morgan.