I do not agree that the LS400 aped the Merc.
It looked revolutionary when it came out, it was sleek and beautiful and still is, probably, the most beautiful car body shape of its era and beyond. Some say it is bland but I believe the shape reflects the aerodynamic which was also miles ahead of most of the competition.
Remember the big Merc S600 of the time was butt ugly and you hardly ever see them anymore.