I have the HD quest and have had a lot of problems with the mount. When it goes off, it is because the mount for the GPS is losing contact with the Shoe. I fold a matchbook cover in half and wedge it into the space behind the GPS and shoe. When the tooth broke on the shoe which goes into the mount on the fairing, I was perplexed. So, I took two dell computer cord wraps ( the big rubber bands w/ the buttons) and screwed them to the inside of the fairing mount and tapped the buttons on the back side and screwed them on the shoe. Now when I ride with it, the rubberbands hod the shoe to the mount and the matchbook keeps the contact between the shoe and GPS. Sound like fun?
The idea is great, but the two part system and Harley vibration on cheap plastic doesn't work. I told my dealer to put me in the upgrade list.
All that said, the gps works great. I also have a 2620 Garmin and it works fine in my car and on my Heritage with the handle bar bracket from cyclegadgets.com