Spent the last 3 days riding the rain in Colorado. I have a Tulsa windshiel and must look through it or stand up to see over. The rain beaded on the shield and greatly decreased visibility. As I understood it you can put nothing on a Tulsa windshield. I called Tulsa and they said that I can use something called Sumner 210. Does anyone have experience with this product? Does anyone use something on their Tulsa to help shed the water in the rain. My wife loves the shield so I do not want to switch.