In Waze Setting menu (press Gear icon from map screen to get there)
Scroll down to "Advanced Settings: Sound & voice". Press the arrow there.
Scroll down to "Advanced: Sound output". Press the arrow there.
Press "Play as Bluetooth phone call".
I've not used that setting in a long time, so I don't know how it'll do on the M3. But give it a try!
--Woof!