I took these pictures a moment or two after I shut off the car. There was a light drizzle that day, and the rain drops highlights the pattern where the streaking occurs. My iPhone couldn't capture it well enough to show the actual streak.
Basically, as the wiper goes to the left the window is nice and clear, but on the return stroke to the right it leaves a water smear about 4" wide right smack in my field of view.
I did a google search yesterday and found a bunch of people suggesting some Bon Ami and elbow grease, followed by an alcohol wipe down. Tried that last night and just now drove in the rain again, with improved but not perfect results. I'll give it another round tonight.
I'm still wondering about the spring tension in the wiper arm.
BMW Ergo Zoom
IMHO: E39 < E60 > F10
2011 F10 535xi (ED July 15, 2011)
2008 E60 550i (ED July 22, 2008)
2000 E39 540i (Retired)
Member BMWCCA #402733