I dont know how to fix your existing spots, but ive used this product for about 8 years sinceit was given to mee by the chemist who formulated it after I asked him if such a product existed. I think nowadays it might be called a drying aid. We have very hard water here in OC. My technique is to blow 80+% of the water off and then mist this over every panel. Wipe the car down quickly and evenly. No chance of spots now.Finish with quick detailer and a fresh microfiber. "Aqua Gloss".