I have a brand new E350 which sometimes refuses to shift into reverse from park. Shifting to drive instead and then back to reverse usually does the trick. This happens only occassionally, and of course it would not happen when I took it back to the dealer for repair. The car hasn't left me stranded yet, but it is unsettling that a brand new car seems to exhibit transmission problems like this. I wish it would just break down completely so at least the mechanic would have something to work on. When I had it in the shop, they checked for faults in the computer but there were no 'events' recorded. Anyone have any thoughts on what might be wrong?