While it's obvious that some people have used the rear point shown in the "rainy day" photos to jack up their box, I sure don't recommend it. As the referenced thread at rentech points out, the rainy day people later admitted they used it because they "thought" it was the right one.
If you've ever had the sheet metal brace off (I have), you'd find that the square tubing used at that rear point is light weight and not even attached very solidly at the top. I'm frankly surprised that it will hold the weight of the car.
IMO, the correct point is the one shown in the Bentley manual, and is the one between the rear wheels at the engine cable loop. It's a big, solid frame member, not a wimpy piece of 1 inch square tubing.