Thank you for the reply.

Based on my test, I suspect the issue is with the Moto phone or Andoid, since the Windows phone works well with the same vehicle audio system. However it is possible that the Windows phone uses "phone" channel to broadcast Here Drive voice. I noticed "Cortana" with a fake phone number on the car display when Here Drive sends a voice. If this is true, is there a setting in the Moto phone to force Google Map to use phone channel for its voice? The phone voice can automatically switch the car audio to Bluetooth for both Windows and Android phones.

-Xiangrui