Thats the sway bar link that should be connected to the hub on the back with
an arm.
I think that without this, your car will be unstable and tilt
more than usual at rear, in turns.
Not sure which car in the image, but I think this should be
the correct part?;
http://catalog.worldpac.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=catalog.mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=21E0CC7E425T0DZVCW&year=1993&make=MB&model=190-E-005&category=L&part=Sway+Bar+Link
br,
syljua