Hi, I have fitted a set of aero arms from a MK4 Golf but I have an issue in which the passenger wiper hangs over the windscreen seal? The wiper blades aren't genuine Audi items (came with the arms) but I *believe* they are the correct size? Drivers side is 21" and passenger is 19". Looking at pictures on other cars, this isn't an issue? Mine: Any thoughts? Does anyone have the actual measurements of the genuine Audi items?