If the phone is connected to a car by Bluetooth or USB, assume it's the driver's. If you get it wrong, it's just a minor inconvenience (unplug if you really need to use those features).
This would be a disaster for me. Whenever my wife and I are traveling in the US she is the driver and I am the navigator. My phone will be connected and I have to "translate"/enhance Waze directions for her and take care of the music. So none of that would be possible anymore. Would be the same BS as some cars that won't allow me to pair my phone while my wife is driving. I guess we would just have to use the phone speakers then.
My partner and I will trade off who drives, but mine is always the one on Bluetooth. This would make it super annoying for me to navigate to places as a passenger, and I'd have to use her phone, which then shows the defects in the system.