After 3 weeks of waiting for part(swaybars) which had to come to Osoyoos,BC from USA,and when those are not any more plastic,but steel ones,my garage replaced it.
However the problem described in my post many weeks ago (just strange ratling soound emanating from rear side) is there again without any change.We have to look for another case,which we will do next week.I will keep all posted.Thanks MVK and leathermang for your help.If someone else had this ghost in 300SD ,tell me.