Schtum,
I was looking at a BMW Navigator in a dealership yesterday that had been mounted on the top rail of the windshield brace on a brand new R1200GSA. I appreciate that the Navigator mount/cradle precludes the use of the sockets on the side of the zumo, and that is one reason why I don't want to go down that route.
The zumo I already own is perfectly good, and also has the extra maps for the USA that I need, so I have both USA and Europe maps. The chrome clamp (I am only going by what I was told by the dealer, and I am new here so am no expert) was a BMW part - sorry I don't know the number - that may well have to be ordered as an extra, I don't know. The clamp has four 1/2" long plastic spacers/isolators (or that is what they appear to be) that connect through to the back of the Navigator cradle which has identical spacing to the standard zumo 660. Therefore it will fit. In fact, the Navigator cradle appears to be the same as a standard zumo 660, but of course has a larger overall footprint to allow for the buttons on the side. If you compare the two side by side, you will see what I mean.
Unfortunately, I did not take pictures so cannot show you what I saw, but the salesman told me that the bracket is available seperately if I speak to the parts department.
Garmin's own lead looked more substantial to me when compared to the BMW specific version, and it also has the option to plug in other components (whether I do that or not is a seperate issue). I don't really want or need my zumo to switch on and off with the ignition because I will either switch it off manually, or simply remove it from the mounting completely.
I previously had a 550 and had to remove the whole mounting from the bike every time I stopped for gas/petrol, food, etc., for fear of theft, and so feel that for me, using the "BMW" chromed clamp part in conjunction with Garmin's standard mount is the best solution. In fact, this is similar to what I have on my current machine. It is wired straight back to the battery and I have never had a flat battery due to current drain.
Not knowing how the BMW system works, I was led to believe that if you connect something straight to the battery, somehow the system detects a current drain and that this can cause problems. This may be totally wrong, but that was another reason for asking on the forum!
Thanks again for the help and advice.