Just thought I'd add some info here since I have some experience with the Chevy MyLink system now...
I recently purchased a 2014 Chevrolet Trax LTZ and it has a 7" touchscreen interface with their MyLink system built in. With an iPhone, that means while it is connected to the usb input it will send the BringGo navigation software from your iPhone app to the 7" screen. It will do the same for the TuneIn app, Stitcher app, and (in the U.S.) Pandora app. Apparently with Android it will do this via Bluetooth. Having a nav system that can be viewed on the vehicle's screen but updated through the phone is a nice alternative to pricier installed systems.
Through bluetooth it will play music off the iPhone, do phone calls, do Siri Eyes Free, etc.
There is actually no CD player with this system but in my previous vehicle I barely ever used the CD player anymore so I was fine giving that up (I also have XM in the Trax, so I have plenty of music options anyway).
Overall I'm pretty happy with the system. GM also lets you start your car and unlock/lock doors via the OnStar remote iPhone app and apparently that is free for 5 years if you activate it during the OnStar trial period. I'll be setting that up soon. I think it would be great to start my vehicle in the econo-lot at the airport after my plane has landed :-)