This is my Garmin zumo 350LM freshly mounted on a Malaguti Spidermax GT500 maxi scooter.
The mount is the standard Ram Mount system which came in the box with Zumo. I've drilled an opening in the plastic under the windsheld from which the 1" Ram mount ball protrudes.
The mount is powered - I've connected it to the ignition so that when I turn on the bike it powers itself, and when I cut the ignition the zumo automatically goes to its shut off delay sequence. Also, I've fitted a separate fuse for the zumo which is easily accessible from underside of the front fairing - the fuse is in a rubber, waterproof marine case.