If you're looking to keep the factory radio and add your ipod/iphone in a way where it will control it through your SWC or radio, the only way would be to get your hands on one of these guys.
iSimple ISNI572 iPod/iPhone Interface Kit for Select 2006-2013
Edit: Honestly though, you can do so much better than the factory unit in there... I'd probably recommend just taking it out and going aftermarket.