Mercedes uses 5x112 pattern. They do have some really nice wheels. I think their offset is way off of the LS's offsets. Once we tried to put my rims on my friend's W126 86 420SEL Benz, the bolts were off, also the rims was sitting way inside, too close to the car, so the original mercedes wheels would be too "out" for the LS.
Most of the bigger Mercedes car's (S, SL, CL, etc) wheels are interchangable, but I don't think that any of them would fit the LS.
The LS would look really sweet on some 18" or 19" AMGs from CL55.