I'm awaiting my 660 to eventually be delivered from Amazon - do you need anything else than what's in the box to fit the 660 to the screen support on an 08 1200GS??
And is one of the cables from TT still the easiest option to plug it into the bike electrics?
Hmmm...not having an 08 GS (or even a BMW) I can't say for sure, but...
...the cradle supplied is a standard, 4-hole AMP design, so it will fit onto any 3rd party bracket, such as TT's highly engineered mounts.
The handlebar clamp does not include the adapter to convert it to the 12mm diameter required for most bar mounts and handlebar braces. Is it a 12mm diameter bar you refer to? (You can get the adapters for about a fiver from GPS Warehouse or Buybits.com etc)
The cable supplied, provides a permanent power option, and a 3.5mm socket for audio, and a 2.5mm jack socket for a microphone. These latter 2 will allow cabled connections to, say, an Autocom headset/speakers and/or a separate in-helmet mic for phone calls etc.
Regarding the permanent power...the cable requires connecting directly to the battery, with pre-crimped fork-type terminals, and an in-line fuse on the positive feed.
However, these can be easily removed and wired to a BMW DIN (Powerlet) plug if you wished.
Double-check the power issues (if any) with the BM's non-standard CAN-BUS arrangement with those more knowledgeable with me, on the latter option. I believe hard wiring will not cause an issue, but PLEASE check before you install, as I think adding sockets and removeable electrical items can be dangerous!
I'm about to start a thread on wireless/bluetooth headset options with the 660, if you're interested.
Yoy