Linuxluver: AA Glass replaced my Tekna windscreen after it was smashed only 10 days after I got the car. It was a piece of chip thrown off the top of the wheel of an incoming truck speeding through road works on SH2. I now always slow right down to the posted speed. Driving to fast is how wind screens gets smashed.
Anyway..... My rain sensor works fine.
Well, good to know that it can be done at least. The smash didn't happen at or near any roadworks, just small stone falling of incoming truck while both driving approx 90-95. My dashcam shows the event very nice. Nothing you can do about that, just unlucky I suppose.