This is how I have my zumo mounted on my BMR shelf. The bracket is also sold by BMR (around $9), screws into pre-drilled holes in the middle of the BMR shelf, and has two die-cut "channels" allowing for multiple attachment options for RAM mounts, the included ZUMO motorcycle mounts (so you don't have to use the handlebar stuff that comes with the GPS), or almost anything.
The blue cable is for audio, I ran that through the the center hole of the BMR shelf, through the hole next to the map light (which I enlargened with a dremel, CAREFULLY). Did the same with the GX-30 XM antenna cable (which I used the extension cable, so I can attach it to my top case lid).
For permanent power, I patched into the maplight wiring as well.
I like having it higher up, so when I look at the GPS my eyes aren't WAY off the road as they would be if the screen were on the gastank (like the "OEM" mounting position BMW uses). But, to each his/her own.
(If you're looking for a BMR Shelf, check out ltparts.com...Tony usually has good used ones and I think he's an authorized vendor as well).
For non-Zumo users, particularly those picking up Tom Tom ONE GPS models, this should work.
Tom Tom One buyers, check out these options...
this would attach to the bracket I used and mentioned
this would raise it even higher, if you needed that
(personally, I wouldn't mount the thing on the handlebars because of the power cord issues, but hey, you're adults, do what ya' want!)
Hope this is helpful in some way, drop me a note at [email protected]
if you like