To anyone wanting to adapt and as I am aware TT support has been suggesting (or may be relying on) a RAM solution for the various bikes on the market.
RAM will adapt using the diamond base (two hole) fixing just as the images posted by Sn1p3r which attaches on the existing TT Rider bracket plate/cradle.
So for tubular handlebars as on the GS use either a RAM-B-149Z or RAM-B-149 or even RAM-B-149ZA if a shorter arm is needed. Add a RAP-319 for a 1200GS if attaching on to the oval rail above the clocks.
For RT's use a RAM-B-238,RAM-B-201,RAM-B-252 set up
For Migsel speedo bracket with 1" ball post (as mentioned in another thread) use a RAM-B-201-A and RAM-B-238
For interlopers and others with Goldwings, STxxx Pan European and similar then go for a RAM-B-174 set up and attach on to the handlebar/reservoir clamp.
SteveH.. 'the car cradle to switch between bike and car' .. use a RAP-224-1 and RAM-B-238 so you can migrate b'tween bike and car, or just get a RAP-B-166 mount plus the TT Rider cradle.
.. No pics as yet, I shall give links when I have them up.
This may slow my mail box
RAM-man