[clickman]

Yes, I gathered it was about the water falling from the sky as your original post said "rain sensor". Hard to confuse that.

I found the original box and instructions I got from Porsche. It's made by Xanonex. The Xanonex instructions don't mention adjustability, that I can see. Yet the Porsche instructions do - increasing or decreasing wiping cycles - whatever that means.

As my memory refreshes, I now seem to recall that my relay also didn't have any adjustment.