Can the audio routing switches be configured to retain mono car announcements (reversing sensors, fuel alerts etc) when in a voice call?

The Selective Un-Mute feature of the TK30 will allow audio from the vehicle's entertainment system to continue to be heard on the desired channel during a handsfree call.  This allows for parking sensor tones, navigation prompts, or other vehicle audio items that utilize the entertainment system speakers to be heard while in a call.  This pass-through does not function during Music playback when the Line-Out setting is not selected.