How do you get really dirty windows clean?

Hello Tina! Did you try using some vinegar and warm water and then wiping dry with wadded up newspapers. This usually works well for me. Sometimes certain paper towels will makes things look smeary in the sun so if I have to go back and wash the windows again I use the wadded up newspapers. https://www.wikihow.life/Clean-Windows-With-Vinegar

Vinegar and water with a couple drops of Dawn dish soap. You have to be sure to completely buff your windows dry or you will have those streaks.

straight rubbing/isopropyl alcohol clean cloth no fabric softener on it (leaves streaks and smears) no paper towels they are made with chemicals to increase absorbancy leaving streaks and smears,pour rubbing alcohol on one cloth wipe window with it dry with 2nd cloth ,wipe insides of glass one direction-horizontal-and the outsides -vertical-or whichever this way you can tell which side you have missed anything, if you have microfiber cloth it works best for the drying leaves no lint