Never enjoy interior window cleaning. I came across Out of spec detailing on YouTube and he was using this 50/50 combo. Ive only used it once since buying it, but it cleaned without streaks/smears. Usually I have to do a quick rewipe a day later after noticing the areas that weren't clear. Side note, he reccomended using Adam's brilliant glaze as step one if your windshield has a lot of off gassing. Mine never gets that bad, but years ago I used a very similar product from a local roll royce dealership in England, by auto gylm. Goes on like a car wax, so when it dries you can see if you missed any areas. After buffing off the windows always looked great and slick.