Just purchased a 2011 C70 and having trouble getting incoming call volume loud enough to hear caller's voice and caller's are complaining there is too much background noise or humming to hear me when I am talking. I already know about adjusting the incoming call volume by using steering wheel keypad but that doesn't help. I also have bluetooth volume on my cell up all the way. Climate control blower turned off doesn't help either. Pretty bad when a car in this price range has such lousy bluetooth capabilities. Anyone have any helpful tips?