Be sure and take care not to polish too long in one area or the glass will overheat and crack. I choose a cool day in the shade and continuously touch the glass with my bare fingers, when the glass starts to get warm I move to a different area and so on. The internet has plenty of U tube videos also. I also learned that if you use this stuff when the glass is still in the car you need to tape off/mask off as much of the area around the glass as possible because the fine powder (mixed with water) gets into every single nook and cranny then it dries and takes some elbow grease to remove. I used that 2 ft wide brown paper and painter's tape. With the buffing pads on a drill to can sling the slurry all over.