Just an 'update' for this.
New Q3, with factory fit towbar. As standard for the UK, now has the battery charging connection, but not the fridge connection.
Since I had specified 'full 13P', my dealer (Stansted Audi) fitted the Westfalia fridge connection relay upgrade (the wire to pin 10 was already present in the loom). However towball socket did not have the extra (pin 11) ground connection, so they checked back with Audi, and added the extra pin, and wire back to the boot.
Now functions correctly.
Upgrade parts cost them about £30, and it took them a couple of hours (dismantle the socket, add wire through the sleeving, and pin to the plug etc..).
FOC to me, since I had seen the 'problems' in this forum and elsewhere, and made sure I specified that I specified this....
The flip down with bowden cable, really is nice, since it prevents you having to find somewhere to hide the removable type ball.
So if you are OK with just charge power, the factory fit unit is now OK. However if you want the fridge power, then make sure to cover this when ordering.
Best Wishes