I had forgotten to add this information to my earlier post about my review of the P85+ loaner. Partially as the problem was so minor, but also the problem was so strange.
Twice when driving the loaner, the windshield wipers turned on ever so slightly, and quickly turned off. The blades rose about 5″ up and then retired back to its resting position. In both cases, I did not turn on the wipers and in one case I had a witness. Since it is summer here in California and we had a very dry winter, I actually think I have only used the windshield wipers on my Model S only twice. I actually could not tell you where the controls are before I wrote this post.
In both these mysterious cases, I know I did not accidentally hit the lever as my hands and arms were in front of the steering wheel. These odd occurrences only happened in the loaner in the four days I drove it, never in my own Model S.
In order to write this post, I decided to take a photo of the windshield wiper system. To my surprise there are two asymetrical windshield wipers, one large windshield wiper, and a smaller one on the passenger side shown in the photo below. It sure has been dry here as I did not even know I had two windshield wipers. I also experimented with the mechanism for turning on the windshield wiper and found it to be quite difficult to turn on accidentally as it requires a turn of a knob at the end of the windshield wiper control, not an accidental brush of the entire stick.