Lots of people hate rain sensing wipers, but I got them spec'd on both our cars and they are usually okay - now and again they drive you mad by either "being late" or running flat out for short periods - by mainly they are "good" and useful.
I had the factory-fit rain sensing wipers on my Mk4, and they worked brilliantly. When I ordered them I was a bit sceptical they'd be of much use, but now I wouldn't be without them. I've had them on both Passats since (it's exactly the same unit).
The sensor is attached to the rear-view mirror housing, and the rain-sensing wiper option meant you got an auto-dimming rear view mirror too.
With a bit of work looking up the parts in ETKA you might be able to get everything you need, although cars that had it factory-fitted had a small round shallow recess in the windscreen glass for the stick-on sensor to sit in, not sure how well it would work if you fitted it to a normal screen.