Removed both rear arch liners from my 06 W203 today , nice idea to have removable liners , less of a nice idea as they trap mud.Still a good clean up and waxoiling should help prevent any rust forming although to be fair there isnt any as yet .
Prevention is better than cure so if your using your Merc all winter its a good idea to get all the crap out and clean it up - and post winter as well
