2016 Fusion. Bought Jan 3 2016. About 2 months ago, noticed windshield (interior) was getting filthy. FAST. Cleaned with microfiber and few drops of h2o. No more than 2weeks later, noticed it coming back. Cleaned with microber and few drops vinegar. Fast forward 2 weeks. Same film. Cleaned today with windex, and I hate windex. But it was the only 'glass cleaner' under the sink. Could it maybe be the cabin filter? Any other ideas? The residue is so bad, my greasy fingertip makes it look clean when I swipe at it. I though maybe my wife was hitting an e cig, but I was the only driver in the last timeframe...