Can anybody confirm if the 2015 Mitsubishi navigation will work on my 2014 GSR? Looking to upgrade from the non-nav.

As far as I know only the 14-15 radios are swap-able between those two years. I had a touch radio in my 2014 mr, I replaced that with a 2014 oem nav and it was plug and play. The dash wire harness was all there ready for nav. What I needed with the oem nav was the gps sensor which plugs into the back of the nav. And one short harness that went from the nav into the dash harness which, which was right there directly behind the radio.

Hope this helps