I have a 2006 GXP and this will be my last GM car. This was my fifth Pontiac. Yes, the 2006 has the speaker hum or the hum may be from OnStar that it is not compatible with the Monsoon speaker system. I have been going back and forth with CAC and was told recently that the New Jersey representative for my dealership said that the dealership offered to take my car to a Sound Diagnostic Center and I declined! I said that is not true. I haven't been to my dealership since Oct. when I had an oil change. I then called the dealership and spoke to the owner. He talked to the service manager and they both said they never offered me that and I said I know that but that is what CAC said. The owner said there is no remedy for this and anyway, he said, the radio would be fixed here, not sent out. CAC also said I had 90 days; the owner said you have a three year warranty. He said all the CAC wants to do is get rid of problems! Now, this morning, the car had not been used for over two days and keep in mind that OnStar is always monitoring the car but if it is not used for 48 hours they are not monitoring it because they don't want to wear down your battery. Well, this morning when I opened my door there was no humming. Now, I'm convinced that it is from OnStar. I would like to know who the New Jersey representative is who said that I declined to have my car sent to a Sound Diagnostic Center, which was not true. But after thinking about the Sound Diagnostic Center for a few days I was thinking that I didn't want any radio place messing around with my car. If GM can't fix it. How can some radio shop? Another thing last week I noticed that the words "Push Audio" on the radio don't light up as do all the other words above the buttons. Also, I live in North Jersey and used my car in the snow and the stock tires were fine!!!