I've just had the opportunity to take a photo of my SatNav mounted over the transmission tunnel on my +4. The mounting disc (Halfords) is stuck to the underside of the dashboard.
I use a similar arrangement. A mounting disc stuck to the underside of the glovebox, with a swan-neck TomTom mount suckered to it, extending out to put the sat nav display just out from under the dash on the passenger side. This places it in the shade of the tonneau cover when I'm driving solo. When 'er indoors is with me, she generally holds it, or more usually we dispense with it altogether and I simply go where she tells me
