Hallo,
My mount is screwed onto a LT specific clamp which goes through the maplight. For details please see following link to the German BMW bilderpool. I put some pictures there. If you cannot have access I can also send the pictures by mail. Negative point: No maplight nomore. But be honest; do you really need it?
http://www.bmw-bilderpool.de/Quest-Montage
This clamp is offered from a small german company (
www.motorrad-herden.de). That guy modified a baehr audiocable with a 3,5mm stereo plug to fit into the 3,5mm socket from the Garmin cable. So the sound goes through the baehr intercom. For power supply I used the existing power supply from the maplight. Advantage is that the power is cut if you lock the bike. (conection red-violett/ black-brown). The location is perfect. Even if the sun is nearly down you can see still everything without problems.
The protection is better then on the handlebar even if the Quest is designed for outdoor use.