2008 Acadia - Xm Radio Problems

[Swiper]

I just purchased a 2008 GMC Acadia equipped with GM Delco/Bose audio system. Everything sounds great except for the XM Radio. There is a constant wine noise in which the pitch and intensity increase and decrease accordingly with engine RPM. The noise is barely noticeable when the engine as at idle, but it makes the XM unbearable to listen to in normal driving conditions. I called the dealership the day after I purchased the vehicle and they told me to bring it in and they would install a noise filter. About a week later, I took the vehicle into the dealership and demonstrated the problem to the service rep. The service rep called me later and said the radio works fine and that the noise I was hearing was caused by 'signal loss due to interferance of buidings or other objects blocking signal.' The service rep said there was no noise filter to install and the radio worked fine. I felt this was an insult to my intelligence. This is the 3rd car I have had with XM Radio. I understand that XM radio is not crysal clear and signal loss does occur from time to time. However, I can tell a difference between siganl loss/interference noise and noise caused by alternator/poor grouding. I'm taking my Acadia to another dealership to see what can be done. Anyone else experience or hear of this problem? Is there an easy fix?

 

Thanks -