Hi
i know what you mean,
though we have worked on such formula and made it , after deep thinking we decided not to launch it for now since price wise it wont be so cheap for car shampoo , to get it to work really hydrophobic it need to be high concentration while cleaning well the surface too, so for now i think the best way is to have a good cleaning shampoo and spray sealant after, Hydro2 will do you that job in no time once you finishing washing your car.