Best Place to Mount Cell - Based GPS Tracker

[iGot2Fly]

I have a new Phantom 2 Vision+ on order, and I am planning on adding a cell based GPS tracker to it, just as a safeguard in the rare event of a Flyaway or if I somehow loose the Phantom during flight. In particular, I am think about using a the PocketFinder, which is just 1.4oz. Does anyone know if there is a spot on the Phantom 2 that is best for mounting this, for weight balance and to keep from any kind of signal interference?