I take pride in keeping my car clean and looking nice, and sometimes I think automotive windows were made to keep cars from looking clean. They can be such a pain to clean without having streaks and smears all over them. I have tried Windex and tons of other automotive windos cleaners, as well as paper towels, micrfiber cloths, and even newspaper to clean my windows, but the best thing I have found so far is Stoner Invisible Glass glass cleaner. It comes in an aerosol spray can, so it is very easy to use, and it doesn't take much so one bottle will last a very long time. After I apply a small amount to a window, it clean it and buff it dry with a microfiber cloth. Most of the time this results in a beautifully clear and clean window, with no streaks. On some dirtier windows I have used a few applications, and buffed the window for a little longer, but I have always been pleased with the results.