So, last night I got chatting with a friend and we decided to play with the old ram ball/handle bar mount
The headstock mount I had for the aprilia tank bag looked like it could be a suitable start for a new mount point....
I disassembled it and then started to think a little.... I also had a close look at the ram mount....
one short hacksaw job later, I had the ball and short bar in my hand
I tapped the aluminium of the shaft with a 4.8 drill and a size six tap
I used a quite long size six bolt and the original parts of the aprilia mount and reversed them - the nut end of the bolt coming up through the expanding plastic shroud
so, here we go:

this will give me my garmin mount point and still allow use of the tankbag
(Yes I know I could have bought one, but where is the fun in that!)
Cross posted to other falco forums for others to consider it as an idea - and apologies for the crap photo - it was late, I was drunk and it was my camera phone.....