Bluetooth priority device

ricpiga

I notice that my earphone BT has priority connection theme BT car sistem, but I want the opposite. I mean, I'd like car BT become prevalent to all other BT device.
Instead, when I get inside car, I have to open BT section and connect manually. Every time! Instead, when I go out from car the BT earphone autoconnect by himself (not always). When my iPhone there was no problem because You can have multiple BT connection. Now I know I can't pretend the same for this price, but I'd like to know rule about priority device.