Why does my rain repellent leave a haze or streaks after applying it?

Haze is usually excess product that was not buffed off completely, or product applied to glass that was not perfectly clean. Humidity, cold glass and applying too much product make it worse. Buff the glass with a clean, dry microfiber towel, then use a second towel for a final pass. If the haze has cured, a glass cleaner or light glass polish followed by reapplication may be needed.