One problem related to brake disc caliper has been reported for the 2005 Mercedes Benz E320. The most recently reported issues are listed below.
I had sudden and almost total loss of breaking. Fortunately, this happened in a left turn lane at a traffic light in a rural area so there was little danger. However, it could have been much worse had this happened in interstate traffic. I was on a slight hill and was able to get the car stopped without hitting the car in front of me, but I had to press the pedal all the way to the floor. I then put the car in park to try and diagnose what had happened and then the car locked up in park so it couldn't even be pushed. The deal wound up replacing the sbc pump and the left front brake caliper which was damaged during my efforts to stop the car. The car has 110,400 miles and has been dealer maintained the entire time.