Yesterday while driving down the highway, I had a VW Beetle (gas) in front of me that shot fluid from the exhaust. It coated my entire windshield and front end, and when I used the washer fluid, it created a white film on the windshield that I could barely see past. I pulled into the nearest gas station to use one of the squeegees and that minimized it but did not get rid of it. Only solution that has worked for the windshield is dish soap. What could this substance be and how do I get it off of my car without damaging the paint?