my buddy is parting his old 2013 gt and asked me if I wanted his OEM navigation system to put in my 2013 gt because mine didn't come with one, and my question is will it fit and will it be able to work in mine

 

Yes, but make sure you do not need a 4-digit code when you put it in yours, and if you
do, make sure he has it, or it won't work. From what I have seen, with FORD, there
are no security codes on their radios. None that I have seen thus far for the S197 Platform.

You will need to wire a GPS antenna.