Car Line Specific UX
Normally each passenger has one infotainment display. In bigger car, all backseats share one large display, or the pillar to pillar screen.
Bluetooth devices, phone, console, AR glasses, and headset, are managed in one popup with a single button serving as an on/off control.
When multiple passengers have their bluetooth headsets connected to pillar to pillar screen and one connected phone, an incoming call forces all to participate.
Looking deeper onto the software level and competitor's products, I learned bluetooth headsets contain two protocols: Hand-Free Profile and Bluetooth Audio, enabling wireless voice and sound respectively. For most BT headset, HFP and BTA are coded together, so to better redirect the call, these two protocols should be separated.
When multiple BT headphones is connected to pillar to pillar screen, passenger can choose which device is for audio output while the rest serve only as audio input. Separating one function into two for better user flow and UX logics happen quite often in the automotive industry.
