Lkchris is right. I read about their patented mono-wiper years ago and I can't remember where. It works on an eccentric cam and is able to cover approx. 88% or 93% of the windshiield area. Jaguar has a mono-wiper too, but it's no comparison to MB - they don't use an eccentric cam, just a regular sweep. It was done with safety in mnd though. Kind of like how every component in the engine compartment has a "destination" upon impact, anything to avoid penetrating the passenger cage.