I would never own a vehicle with OnStar. Whether or not the owner activates he can be listened to and tracked and it has been done. Don’t tell me about all the technical reasons it can’t be done, it can be and has been.
Your cell phone can be used as a clandestine listening device if it is in the interests of people or agencies with the power to order it. Think about your cell phone as a tiny computer. It can be imbedded with secret and hidden software. Not a common occurrence, but it can be done.