peter
POTM Winner - February 2017
believe or not but mine has been on for over 2 years now and its still same ..
maybe try claying the windscreen and then use a windscreen polish (like auto finesse vision) to get rid of the stuff?
i've used rainX in the past, terrible persisitent judder and smearing. took a lot of aggressive glass cleaner and a new set of wipers to get it of the window.