I have a 3 year contract on my portable XM radio which I use in my camper and at home. I would like to use it in my 2008 Tahoe instead of the unit that was factory installed. (to save the extra $ per month) How would I be able to connect into the antenna and run my output through the speakers of the radio? Is there any way that I would be able to use the factory tuner with my radio? Any help would be appreciated.