We almost got into crash the other day, our 8-year-old kid got our attention that rear seatbelt got very loose and did NOT retract back at all. he almost hit his head. when I asked him if it has been like this he said no, it was tight when I buckled it in. We tried several times to retract it manually with no luck. I checked online and I have seen people complaining about the same thing. we have been lucky we didn't hit the other car then my child will be seriously injured. This is a very serious safety requirement. I hope Mercedes Benz will take this very seriously as well, before others get hurt.
NHTSA ODI 11695355