Have you tried to adjust the volume while using bluetooth? Try making a call to your wife using the bluetooth in your car and while she is talking try turning the volume up using the volume control on your steering wheel. If I'm not mistaken you can adjust the volume that way. If you have Nav you may also be able to adjust the volume in one of the menu's...Other than that I would say take it to the dealer. If there is something wrong it should be covered under warranty.