I just purchased an 09 LTZ, I had an aftermarket stereo with navigation head unit, speakers, and a sub woofer put in by the dealer. The head unit is a Pioneer AVIC-f70bt. Since than the Door chime as well as the turn signal indicator noise has been unusually loud. It has been back one to have them turned down, but the volume is still too loud. I was wondering is anyone knew if this was an issue with the new head unit or the car itself? And if this is something I can modify myself or do I need to make another appointment with the dealer. Thanks.