I just purchased a 2005 TL with Navigation and have a question. When I change the settings to voice guided, the system talks through the front speakers but the rear speakers keep playing music. When I have the radio turned up, it completely drowns out the nav system. Is there a setting I can change so the Nav speaks out of all the speakers or does that sound like a problem I need to have fixed by a professional? Any help is appreciated!

 

The navigation speaker is the grille directly on top. Usually it should automatically decrease the radio volume when the GPS talks.

 

This. My audio volume goes down whenever GPS needs to speak to me.