I corresponded with you earlier this year regarding the severe corrosion developing underneath my 2004 Mercedes-Benz C-Class, which has 70,000 miles on the clock and a full service history. As a continuation of the story, I was driving last week on an A road when there was a loud clonk from the rear and the car tried to slalom down the road. Luckily there was no one driving in the opposite direction. Investigation showed that the left hand trailing arm which was badly rusted had broken. The right hand arm was also badly rusted and looked ready to break at any minute so I had both replaced.