If you navigate with your Android Smartphone and Google Maps in your car, then you certainly want, that the voice output of the navigation is transmitted via the Bluetooth hands free of the car. If this is not the case in your vehicle, then you should definitely check if the following setting is set to active on your Android Smartphone in the Google Maps app:
• Play voice over Bluetooth
We will show you now where you will find this option and how to activate it, if it is set to "inactive".
Open on the Android smartphone the Google Maps app and then the settings by tapping at the top right on the symbol with the three bars and then on "Settings". Continue to "Navigation Settings.
In this sub-menu of the Google Maps app you can now see the "Play voice over Bluetooth" option. Check if the checkbox is ticked. If not, then set the tick now. Then the voice of Google Maps should work on your car and the Bluetooth hands-free.