Looks like it's not possible to change bluetooth device when I am driving. When my wife gets in car first as passenger, her iPhone was connected. Then when I get in and drive, its always her music (she has no music library by the way). There is no way to change device until I stop the car (bluetooth devices grayed out while driving). With other cars I had in the past, it's not a problem to change device while driving. Maybe I missed something here?