Seriously, where do they find the engineers who came up with this design?? The grub screw will never let go and the thing will rust itself into place and the stoopid splines will wear out (and that too what a crazy way to attach wipers!!) until your wipers are falling off in the middle off a downpour on the highway. At night.
Same engineer also clearly designed the clip system to keep the window winder handles on their shafts.