For what is worth, and for those who may try it anyway, the 999Q5-KV001 GPS (PNU) will not fit a 2013 Xterra. I took a chance on this since I have access to large machine and composite shop. No joy was found. We milled down the side of the dock (the dock is 205mm wide) to fit the 200mm opening in the dash. While that did let the dock fall into place the angle of the catches do not align with the docks retention tabs.

Hope this helps someone in the future!

My best!