> However it doesn't tell you this, it just doesn't show bluetooth options in the menu anywhere. So I spent hours going through every menu item

Greyed out menu item = This is where it is on the UI, but it's not allowed at present.

No menu item = maybe it's somewhere else?

If only there were some way that someone besides the driver could manipulate the in car system.

My Chevrolet handles this well, using the passenger seat occupancy sensor. If someone is sitting in a passenger seat, it gives the option "I am the passenger" to allow access to normally blocked-while-moving screens.

And the behavior the parent described is just annoying. The device has the capability to know if the car is in motion or not. Permanently locking out the function until the car is turned off and on is dumb.