Driving to Chicago, it was snowing lightly. The stuff wasn't actually sticking to the roads, though they were damp. Sis was driving. On our right, we were about to pass a slow-moving salt truck. It wasn't actually salting the road at the time, but my sister said, "Watch out for the spray!" I was about to tell her that she was being overly paranoid, when we got just behind it. The instant our windshield was within its range, it turned on for a moment and spewed salt right at us. I'm pretty sure it stopped as soon as we'd passed.
Apparently, salt trucks just have it in for my sister, and she has come to accept this as part of her burden in life.