Front thrust arm and control arm bushings can crack and sometimes tear completely. If this is not repaired quickly, damage to the front subframe unit will occur, which is very expensive to repair. Updated control arms (that prevent damage to the subframe when the bushings wear out) are available.
Car Problem Reports
Mercedes-Benz CL600 Front Thrust Arm and Control Arm Bushing Can Crack or Tear
Mercedes-Benz CL600 Problem
Visitor, 2002 Mercedes-Benz CL600, 70,000 mi
had car into dealership 2500 miles prior with no mention of problem...then failure and the entire subframe had to be replaced. OUCH