Vehicle report
Technical service bulletins are instructions a manufacturer sent its dealers about a known fault. They are not recalls and the work is usually not free, but they are the clearest signal of a problem the manufacturer already knows about.
LI27-20-P-051537
MERCEDES: VEHICLE JERKS DURING GEARCHANGE, HARD 1-2 AND 2-3 SHIFTS, TORQUE CONVERTER LOCKUP CLUTCH NOT ENGAGEABLE. MODELS 212, 216, 218, 221, 251, AND 164. MODEL YEARS NOT GIVEN. *KB UPDATED 10/11/12. *PE
Complaint counts are reports filed with NHTSA, not failure rates. A common model collects more of them than a rare one that breaks more often.