So first off, we keep talking about legal subpoenas and so on, but you -may- very well have given your consent already when you purchased the vehicle in one form or another.
E.g., 'by purchasing this vehicle you grant your consent to ... personal data and driving habits ... third parties ... law enforcement...;'
Or 'Big Car Corporation retains all rights to vehicle software and applicable collected data ... and may at its discretion share data with ... third parties ... law enforcement ... insurance....'
In my post above, I intentionally tried to sound like a delusional paranoid to be sarcastic. There is a reason police cruisers use laptops looking things now, and it's not just so they can surf porn while on duty. Just because you can choose for your phone, vehicle, tablet, whatever to not display certain data, does not stop it from from being collected or block others from viewing it. How do they know to tell your navigation which roads are heavy traffic, blocked, have accidents or construction? Because you send data and they send it back.
That said, you may insist you don't want microphones, GPS tracking, cameras and so on, so you might not have access to it, but it will still be installed (cheaper to do it that way), and if it is there, it can be accessed. I mentioned IMSI catchers (you can google them). IMSI catchers--old tech--can be used to trick your phone into thinking it is communicating with legitimate systems without knowing it is between you and them. At that point, it can send to your device information which the dev. believes is legitimate and alter the software. IOW, now turn on your microphones, cameras, GPS, key loggers (texting), etc.
In the end there is nothing we can do about it except to not use such devices. For every one who doesn't want it, 10 more just can't live without their navigation, instant updates to social media, their 'Ring' doorbells and home security, and so on. So combine the reasons of 'common good, crime prevention, a majority of users who don't care, corporations that make money from it, have you sign disclaimers and away your rights to privacy to protect themselves from your lawsuits, etc...,'
And 1984 levels monitoring of the population is childs-play. Most of all, they have convinced the population life is easier with them--which makes people beg for it, demand such overwatch--and so they grin and give the people what they want.
B.E.F.