Can you not just physically disconnect or shield the network antenna (assuming you own the car outright, i suppose if it's financed it might be trickier to do that legally)?
If you're lucky enough that your car can continue indefinitely without a network connection, it's possible that you wouldn't notice these features being gone. Realistically though, most people would. The solution here needs to be legislative action to protect consumer privacy. Technological solutions fall short.
Which is very worrying when you stop and think about it. If anything that actually matters is reliant on anything not travelling with you then that can not be a good sign for the safety and security of the vehicle. For one thing any vehicle that has any open incoming connectivity of any kind immediately has an attack vector for malware. And in this case that could literally be a matter of life and death and it could literally be used to attack thousands or even millions of vehicles simultaneously.
The closest I can think of to any legitimate phone home feature is an automatic emergency call function that is triggered by a collision or theft being detected. But of course it's very easy to specify that those features may only be activated from the vehicle side and may only be used to contact emergency services.
Anything else like GPS or infotainment does not need to be integrated at all with the essential vehicle systems or emergency communications functions and can be subject to the usual safeguards like any other device - including an off switch if the owner chooses not to use it and requirements to opt in for any potentially intrusive behaviour.
Whether it's unsafe, or a potential security vector, or has any number of other undesirable properties will depend on the specifics. Every vehicle is a highly heterogeneous distributed system, so the systems I've had a hand in designing may look very different than a different platform within the same company, let alone a different manufacturer.
But yes, every vehicle should remain safe without a network connection and privacy should be not only available, but the default.
Which is fine for me and others like me. I don't want any of those connected features to begin with.