This was strange enough that I thought I’d ask here. I was at a strip mall that has a small, somewhat shifty-looking repair shop in it. While I was waiting for something else, I saw one of the mechanics come out to a car in the customer section of their lot with a big bottle of brake fluid. He poured it on a rag and rubbed it onto all 4 corners of the windshield. Just the corners, probably about an 8 inch circle in each corner.
I can’t fathom what he was hoping to achieve, but figured a pro on here might have insight. Any ideas?