I fitted my mudflaps today. I didnt take pictures as i did it but the instructions provided were easy enough to follow.
The front you can see where the mudflaps attach to . Just have to remove 2 Torx bolts from the inner arch liner and one from the under sill. Before you can remove the one from the sill, you have to break off the rubber seal that is covering the bolt.
Here is pictures of the front drivers side fitted, passenger side is the exact same.
Front flaps :
The Back flaps were just as easy to follow using the instructions.
Remove on torx bolt and fit the flap, drill hole for second torx, and drill hole on the underside of the bumper for a plastic panel clip.
And a final picture of both flaps on the car. My car is a 2011 BE S-Line quattro.
Hope this helps in future for folks who want to know if and how they fit mudflaps.