Engine Shut Off Without Warning problems of the 2011 Mercedes Benz GLK350

My car shut down, without any warning, in the middle of the road on April 19th, 2013. At the time of shutdown, all the lights on the dashboard lit up (including the brake light). I took the car in to the dealer on the following Monday having been told by an advisor that they could not work on a major issue as such on the weekend. Since they claimed that they could not duplicate or replicate the incident, they did not know why it happened; therefore, they could not fix anything. They also strongly believed that the car is in perfect condition, and it is safe to drive. In addition, they highly recommend me to take the car in when I run into a similar situation in the future. I was urged to bring my loaner back. Or, they would "start to charge" me. I was in contact with the mb headquarters in NJ. The gentleman who was the case manager told me the same. The April 19 incident is not an isolated occurrence . The same incident happened to me on 2/28/12 when I was attempting to pull into a parking space. The car at the time was less than 6 months old, with about 3000 miles. Working on the advice of a service advisor from the dealer ("it was a fluke; it should never happen again), I did not take the car in. I wondered if any driver of the same model encountered any similar situations as I did.