Well the trick is to buy the proper part. I would never in my wildest dreams buy a wiper blade for my MB at the local hardware store. The other post about the blade not fitting even though it was purchased at the dealer also begs the question. Did they make a mistake on the part no.? You have to bet yes, as MB clearly didn't design the wiper blade to hit the trim.

A couple of clicks in the parts section of this site and you'll have the correct part for your car.

Steve