It might be a common thing on a lot of cars I've owned 4 cars and thisis the first iI can't leave the window open when I'm washing the windscreen using the washers I get a wet arm? Design fault or? Simple case of adding wind deflectors ?
I think this happens to most A3's.......both S3's and my 140TDI did this. It makes it even worse when the rain drips onto the window switch. Heko deflectors do stop it but sometimes they tend to trip off the one touch windows due to the resistance caused by the extra plastic in the window channel.