I replaced all four shocks on my w140 (93
300SD. The fronts are pretty straightforward. However, for the rear
shocks, you need to remove the panels in
the trunk to get to the upper mount points.
The rear seat is too far forward.
In addition, there is a plastic shroud on
the a lower struct, where each rear shock
mounts. This needs to be removed (4 bolts)
prior to changing the shock.