Hi, I have just purchased a new 2005 Chrysler Town & Country Limited with the stock RB1 Navigation 6CD changer but without the Sirius satellite radio option. What are my options for getting a satellite radio subscription to play through the unit rather than as an add on unit? Is it only limited to Sirius? Also, my salesman had said that with installation it would cost upward of 0 rather than the 5 upcharge had it been set up that way at the factory. Does that sound right? Thanks, Marc