Well, got the drivers side mirror fitted today and it was not too bad a job although i was a bit nervous taking apart a 6 month old car!. Hardest parts were routing the mirror cable behind the window guide and replacing the mirror switch trim panel.
It is indeed possible to undo the mirror without removing the glass, however the glass needs to come out to route the cable behind the window guide with one arm up through the base speaker hole!
The interior door arm rest/handle that houses the switches needs to come off to be replaced and Audi decided in their wisdom to use the plastic projections that go through to the rear of the panel as a type or rivet in a few areas and have melted the ends to secure them. I have highlighted them using blue arrows in the pictures.. The very forward end of the handle is also melted over although it also has 2 securing screws so no idea why? I simply heated an old coach screw up and remelted the new plastic projection over as i put it back together.
Once i used a drill bit to remove the rivet head i was able to remove the trim and swap out the switch fascia with no problems.
Refitting is simply a matter of replacing the drilled heads with short self tappers.
I have coded 42 drivers door for drivers folding mirror and it works fine from the switch. Been trying to work out how to make it fold on locking but the option is not there in 09. Having discussed it with DJAlix, it could require both mirrors coding first so that's tomorrows job!
Massive thanks to DJAlix for all his help so far!