How do I switch the XM out of my G6 for SIRIUS?? I dont want to use aftermarket radios that look like aftermarket radios. DELPHI makes a SIRIUS radio. Could that fit in the same spot as the factory?? Any help is appreciated.

You're gonna have to go aftermarket, there is no way to switch between the two in the stock headunit. You could keep the stock unit and get an aftrmarket Sirius tuner and then connect an fm modulator to play it.