I've got a 55 mounted low on the glass just above the dash. I just run the power cord to a 12VDC splitter that's plugged into the pull out tray 12V outlet. Works well, and makes it easy to reach/remove for the endless software updates it gets.
My setup has dangling cables, but they aren't really in the way of anything. They just hang over the front of the dash.
I get everything from Time Zone to Speech Recognition to Software upgrades almost weekly, sometimes more often. I also get Cyclops speed camera updates for places I'm never likely to be anywhere near, and Garmin says they can't terminate the subscriptions.