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 SL55 AMG Front Thrust Arm and Control Arm Bushing Can Crack or Tear
Mercedes-Benz SL55 AMG Problem
Average Mileage: 55,000 mi (48,000 mi - 62,000 mi)