I've just signed up to say @weylandthanks very much for the information you've posted here and everyone else for their contributions!
The Install in my 2013 Octavia Estate went very well. The slightly difficult bit was that the Camera version E which was the right size for the hole didn't have the same type of mount that the original did and I had to califudge some little brackets to get it to fit. Probably the easiest bit was getting the cable through the bellows grommet. I started at that point and sent the smaller connector through the gromet on the end of a bit of wire (I used goss for lubricant - less likely to rot the rubber) and then pulled all the length through to the front of the car and the little bit through the door to the camera.
Other thing I did was take the low route and managed to get the cable through without too much dismantling.
Bloody marvellous!!
Thanks, Mike.