The only thing here is that my V70R at 75k miles has not had anything replaced, and will not need anything in the foreseeable future, and thats going over the same bumps and humps
Yep, my Honda had done 69000 miles of daily driving in London and was continually going over humps and didn't have a single suspension component replaced.
As far as Mercedes are concerned it either has to be poor suspension design or poor component quality.