At 3000K miles, vehicle spontaneously slowed from 60 mph to 10 mph with no warning. Message: PERFORMANCE EXTREMELY LIMITED, Engine light, turtle sign. Tractor trailer truck behind us swerved and narrowly avoided hitting our vehicle. Car towed to MB Dealership. Over 5 weeks, they were unable to replicate the problem, asked us to pick the vehicle up. (they claimed they consulted with MB engineers) One week after getting vehicle back, same incident occurred, also narrowly averting a MV accident. Vehicle towed to another dealership who finally after 2 months they stated that the vehicle is not reparable. MB is re-purchasing this vehicle, as there is a software issue they cannot repair. I have been made aware from Mercedes Benz dealership, that 100 or more of these vehicles have the exact same issue. There have been NO recalls. MB USA is not forthcoming with information. The problem is dangerous.