After trying numerous possibilities, this location seems to work best for me. It blocks the mirror, but I can live without it. The iFly 700 suction mount is attached to a Garmin dash-mount disc, available for $6 or $7 most everywhere, and is self adhesive to the glareshield. See the doc below for pics (I had trouble trying to attach them to the file.)
As a side note, when I wear sunglasses, I use non-polarized. They make the instrument panel more readable and don't block the glare of other aircraft.
Dan
[attachment]GPS.doc[/attachment]