I really like my auto wiper system, much more than I thought I would, and would hate to lose it.

This has to be asked: did you activate it properly? I'm sure you did, just asking.

I don't buy the bubble thing. I have looked through thousands of windshields and I have never seen fields of bubbles. And it is hard to believe they would appear just in that small sensor area.

Also, the system requires a fair amount of mist and rain drops to turn on. This would be equivalent to a huge number of really nasty defects in the glass. And if there were a field of bubbles, the wipers would be on all the time, thinking it was raining.

I think it is either activation problems or a defective sensor. Or maybe whatever module controls all this. I am sure there is a fairly simple electronic test to find out what the problem is.

Lastly, on many vehicles with sensors or other fancy options, OEM glass is used for replacements. Sometimes owners are adamant about getting that little BMW etching back. So, that insignia is not proof that the WS has not been replaced.

Glass shops, especially the insurance-friendly cheapo ones, are notorious for breaking wires, using the incorrect adhesives and all that.

So, back to the testing idea. At least you would know what the problem is.