Yes, RunningTooHot is correct, it is the Exhaust pipe that is in the $^$*^% way. The connection looks to be buried up next the left engine bank, guess I'll just have to go buy some more tools
Chowpit, I did buy those exact Allen wrenchs at Harbor Frieght Tools just last week, what a break-through! The rounded end of the tool is a "God Send" allowing you to swivel the tool where you need to. While your there, go ahead and buy the Torx inverted sockets too, you may need them on Mercedes.
Now, if I can just convince my wife Ashley that a "car lift" installed into the garage floor is not such a bad idea.