The only thing that's really different from a sedan W124 is the
tailgate and rear windows. Those have a tendency to leak. Gas tank is
in the right rear fender instead of behind the seat, and it will have a
SLS rear end -- make sure it had normal ride height and suspension
travel. Extremely rough ride is flat accumulators in the SLS, not a
big job but $200 in parts and some labor. Left for extended periods,
the struts become damaged and they are $600 or so EACH.
Nice cars, I wouldn't swap mine off willingly!
Peter