The chassis was designed and manufactured by Chrysler. Very good torsional rigidity - better than Mercedes - actually on a par with the 911!
Suspension components are another matter! When Daimler bought Chrysler, the LX platform was in final stages of design. The new owners insisted on Mercedes components (suspension; braking control; many electronics, etc.) and forced the parts onto Chrysler at silly high prices.
They are a mix of E and S class parts. Gen 2 cars have the same Chrysler chassis and it appears that most, if not all suspension components were re-engineered and built here - rather than supplied by Daimler.