Adding XM to '08 G8GT...

[BigKID]

My Dad want's XM in his '08 G8GT for Christmas and I need to know if there is a Plug and Play option for this? Do the '08 headunits have the ablity to control a tunner from an '09 or even an aftermarket tunner? Or would you have to swap to the '09 headunit for sat-ready control?
He has a SkyFi unit with a car kit he was using in his previous vehicle thru a tape deck adapter. I could just install that and use the AUX input in the front (or the rear as I have just discovered on this site) of the head unit but I was hoping for a cleaner install in his new car.
Any other options??

[Chewy]

My Dad want's XM in his '08 G8GT for Christmas and I need to know if there is a Plug and Play option for this? Do the '08 headunits have the ablity to control a tunner from an '09 or even an aftermarket tunner? Or would you have to swap to the '09 headunit for sat-ready control?
He has a SkyFi unit with a car kit he was using in his previous vehicle thru a tape deck adapter. I could just install that and use the AUX input in the front (or the rear as I have just discovered on this site) of the head unit but I was hoping for a cleaner install in his new car.
Any other options??

Rear Aux but you need some expensive toys to make it work. Front Aux will get you the best sound quality cheap, but I have used and still have the FM modulated RoadyII that I use in my truck and my G/F's car.