Bluetooth audio when using radio (Google Navigation)

I am trying to get google maps navigation directions through my car Bluetooth when listening to radio. I can do this when the source is selected Bluetooth but I want it to play through car speakers even when radio or cd is playing. Any help us appreciated. I have a S7 using Android 6.0

Google changed Maps so that it no loner uses the default Android Text to speech engine. This means that playing the directions over the Bluetooth mono phone channel is now limited to setting Media Audio to "Bluetooth (mono) (dynamic)".
The problem is that this setting takes two seconds to connect so you lose some instructions. With text to speech this can be controlled.

Other apps still work really well with SoundAbout TTS. I use CoPilot.

The directions are here:
https://soundabout.forumotion.com/t418-using-google-navigation-waze-or-co-pilot-and-even-ivona-for-the-voices

New versions have just been uploaded to Google play that will address various issues on Android 6+.

You can get them now from the Beta section located here (need a login to the message board). There is also Betas for SoundAbout and SoundAbout Pro.
https://soundabout.forumotion.com/f8-download-beta-versions

I tried your suggestion, but there is too much delay between Maps starting the message and car speakers playing it. I am loosing at least half of the information. It's a pity, as I was looking for an app to play Google Maps messages on my car BT speakers (not A2DP)...

Yes, It's too bad Google no longer uses the default Android Text-To-Speech engine. With out that, there is no way to pause the request while the audio is switching to Bluetooth.

As I am not "married" to Google, do you know about another Navigation system for Android which allows to hear the voice through the BT "call" channel? I will happily switch from Maps to it.

CoPilot works great with Text-To-Speech.

Directions here:
https://soundabout.forumotion.com/t418-using-google-navigation-waze-or-co-pilot-and-even-ivona-for-the-voices

Latest Beta here:
https://soundabout.forumotion.com/f8-download-beta-versions