On the windshield, I had the SAME issue. I noticed that i would get a little puddle of water on the left floor mat when sat in the rain BUT not if I drove the car in the rain and parked indoors. Turns out that the rubber shrunk a tiny bit and there was an equally tiny gap as well as said gap being at the bottom of the screen. So, when sat in the rain, the water would collect at the bottom of the screen and seep in. Wondering if the rubber is supposed to start and stop at the top for that reason. Anyway, I just added a bit of sealer and its sorted.
Wipers are beat on these. I've ditched those heavy duty arms as they seem to cause more trouble then they are worth. They put a lot of stress on the wiper motor....which is something you should look at. Beat job but regreasing and inspecting the wiper motor and tracks is a good idea.
