I absolutely agree, one should not have to do this.

I'm not sure this disease metaphor is appropriate. Lots of people have STDs, and lots of those people get married, and, as I understand it, many of those people have a lot of safe sex.

And frankly, I don't trust many of my own devices not to fuck me. (figuratively speaking)

Do you really even own it, if it can be remotely disabled by the manufacturer?

Probably not without controlling one side of the communication. On the cell phone, you would need something that enforces mandatory access controls on what data can be sent over Bluetooth. Ideally a smart phone hacker could chime in. I've never owned one. Another potential option would be to root the car, likely voiding any warranty and potentially creating other liability implications.

Bluetooth is always switched off on my phone unless I am in a situation where I explicitly want to connect to something (this has not happened yet). General good advice is to go through you phone settings and turn off everything you know you don't need. If you don't know, turn it off and see if anything you need stops working.