I did an experiment the last time I washed my daily driver.



I used the 303 Spray Detailer on the exterior windows because they said it can clean glass. I got no streaking if I buffed it dry which was nice.



But my experiment was to treat half of the inside windshield to see if it looked cloudy or I could see it. I didnt notice anything for a week or so, but recently we have had a lot of temperature and humidity shifts as fall moves into our area. What I noticed was that the side of the windshield that I did not apply the 303 fogs up much more than the 303 treated side. For instance, the bottom half of the windshield will be fogged up on the untreated side, while maybe only an inch or two on the treated side.



I dont really have an explanation for this, but I thought I would share in case some of you are battling foggy windshields. My guess is it has something to do with the hydrophobic properties of the barrier the detailer leaves down.