i JUST purchased a 2009 Blue Passion and there is a round disc shaped device on the inside of the windshield that looks OEM, but i have no clue what it might have been or if it is still used by something. i don't see any GPS or Sirius device (could have been removed) and the radio on all the Smarts i have seem to be 'junk', so i don't have a clue.... best guess would be for a Sirius or GPS device, but it looks so OEM, it even has the shading/crosshatching that is OEM behind the rear view mirror, and it appears to have some kind of photo/light sensor on the glass side...
Bill
Bill