Thinking about going with this set up or something similiar...If you are willing to spend $700 bucks on AM Raxiom a couple hundred more gets you this. Not only will this also retain steering wheel buttons and voice command but iDatalink + Kenwood gives you a bunch more options, no extra sat antenna, "My Mustang" App and gauge screen that shows things like A/F Ratio, CAI Temp, etc. Plus you can customize your boot screen and backgrounds. I think iDatalink works with Alpine and a couple others too.
http://www.crutchfield.com/p_794ADSM...ce-Module.html
http://www.crutchfield.com/p_794KITM...iring-Kit.html
http://www.crutchfield.com/p_613DNX8...0HD.html?cc=01
Only reason why I haven't pulled the trigger on this yet is freakin' holiday shopping. Maybe next month...