Well eventually got all my parts together to change from the single din to double din on the A3.
It was a long enough job as I wanted to make sure nothing was scratched or broken during the replacement.
Here's all the bits to do it (if anyone wants part number I have a list)
Cable junction after removing the units...(tidied all that up before I finished)
The hardest bit was pulling out the single din cage, it wasn't meant to come out like that!
Putting the new double din cage in wasn't too bad just needed to take my time.
So I put my GPS receiver over on the passenger side and then put everything back in.
I had to trim down the sides of the Climatronic unit as it now sits lower in the cage.
They make the same units to fit there but I'm not paying 1k for new unit when I can use a dremel and do the same thing.
So here's a before & after pic. As you can see I went for the newer style buttons (from 2009).
Looks a lot fresher than the original imho. Plus the fact I can now do a straight swap in of a RNS-E if I get one for the right price.
The last thing I need to do is to get the harness for my Parrot mki9200 for the back speakers as they have their own amp on the A3.
Will be easy enough to fit seeing as I have tidied up everything behind the unit.
Need to do a scan and clear later too, shouldn't be a problem.