Had a member ask some questions here are my responses.
1. The steering wheel functions are retained through the metra kit therefore you would not need another wire for the app radio in order to retain steering wheel functions and yes I am able to make phone calls via hands free that is if you still use onstar. The only thing you will loose is the functionality of the usb in the center console it will still charge the phone or whatever device you connect to it but it will not be read through the app radio.(I don't know if that makes sense).
2. The app radio comes with an external mic that I mounted on the driver side and I have programmed the app radio via bluetooth to be able to receive and make calls. you have to sync your phone book in order to avoid having to dial each number individually.
3. The issues that I have since install are sometimes I have a frozen screen and forces me to re start the unit. Which then resets the whole unit loosing radio stations time and custom settings. Not a big deal to me. The other issue I have right now is that I am attempting to connect two amps which in the case of this radio there is only one channel so now have to go a different route. Other than that I do not regret this radio I use my Iphone frequently and appreciate the screen size for my maps and ease of use of Pandora and with the new IOS I hope they come up with an update to use SIRI on this radio it would make things so much better having everything accessed through voice commands.