I knew about the cabin air filter. But I didn't know it was the cause, or could help with the film on the inside of the windshield. I'll have to ask the boyfriend about that. Or figure it out myself. Because I just had a big issue with the inside of the window. If the sun hit it just right I was blind for a moment. I cleaned it with vinegar and water mixed together in a spray bottle. Worked great! But now I see a small triangle where I missed a spot.