Rear powered tailgate closes by itself. There is no warning. It closes VERY rapidly. This hit me in the head, but I am mostly concerned with others, such as elderly people and children. It could easily cause a concussion, or worse. I have contacted MBUSA advocacy at 1-800-222-0100 three times. I was told all three times that I would be contacted back within 24-48 hours (business days) regarding this safety issue. It has now been two weeks, and I have not received anything such as a returned phone call, email, etc. The vehicle is at my residence and available for any inspection or test, etc. I also have video of this problem. Again, the rear powered tailgate closes by itself, without warning. It closes VERY rapidly with force far greater than gravity alone.