One thing I've been using for 20+ years that always works is crumpled newspaper. Spray your cleaner directly on the glass, and wipe with a few sheets of crumpled newspaper, turning it often, before it gets saturated. It doesn't seem to matter whether Windex, Glass Plus, or some other brand of glass cleaner is used, but glass always comes out clean and streak-free with newspaper. If you've got a serious film you need to cut, add a few tablespoons of white vinegar to the almost-full bottle of glass cleaner.

If you find that a film is forming inside your glass after only a short while, there may be an unusual source inside the car. I'm guessing you don't smoke, or if you did you'd guess that as a source, but maybe the heater core is leaking? New plastics will out-gas, too, such as new floor mats, a dash mat, upholstery panels, etc., or maybe the source is something in the outside environment that you routinely drive through.

Regards,

Dean