Why does my windshield look greasy or hazy at night even after cleaning?

Night haze is often caused by a very thin film of interior plastic off-gassing, smoke, previous cleaners or oily residue that becomes obvious under oncoming headlights. Multiple passes with a clean glass-safe cleaner and fresh towels are often needed to remove the film completely. Clean the inside glass with one towel and buff with a second dry towel. Fine scratches or wiper wear on the outside can also scatter light and add glare.