If your cured resin is sticking to the curing tab and not the glass surface it has something on it. When vehicles go through a car wash the windshield gets all sorts of chemicals on it as the water is re-cycled. Wax, soap and protectorants from previous washings are found in the re-cycled water. The acid found i your resins will eventually remove any coating on the glass surface, but that takes effort and time. Our glass scrub will remove all coatings and do it very fast. You won't believe how well the resin will stick to clean glass.