as I understand it you can't put factory Bluetooth in any previous year cars. As chevymanger said it is in the onstar and they used a new onstar for '09 models. So you would have to swap out the entire onstar set up on the car to get the bluetooth to work. Dont think it is even possible but if it is not worth the $$$$. This is just want I have read on this forum, as I have Bluetooth and USB so will never update the radio.

USB is so much better then the aux port. My zune in the aux port kept dying cuz I would forget to turn off the zune. W/ the usb it charges my iPod and is never dead when I go to use it.