While not an ARB, I'm running an ironman 40l in the back of my D1 (well, currently it's in my D3 but that's beside the point). Pics are in the build thread in my sig but basically what I did was build a tilting slide to hold it that was raised bc of the shelf I have in the back. The fridge also protruded a little into the gap between the shelf and the rear door, but it all synchs up well.
Illustrates what I mean when it's all packed up, more in the coyote thread.
R-
Ray