My passport is mounted on the lower part of the windshield so that when mounted, it floats about an inch from the top of the console (above the nav section). I experimented with different areas before I decided to hardwire it. I did not notice any difference in the range and I prefer the the lower location since I mostly drive with the sun visors folded down to block more sun. The locations by the rear view mirror just didn't work for me.
2009 M3 : 6MT : Carbon : Silverstone : Fox Red Novilo : Aluminum Trim : Tech Package : iPod :
MODS: Performance Spoiler: Clear Reflectors : H&Rs : Escort 9500ix hardwired : Tint : Macht Schnell Filter : RPI Scoops : Rogue Pulley : Fabspeed resonated x-pipe with Remus Race : ESS Tune: TVinMotion