hey guys ,
anyone got a great product that maintains monofilm or stops the clear going foggy?
Apart from washing with detergent and cleaning after each sail.
Magical product out there?
cheers

Are you sure the window is monofilm? The reason I ask that is because vinyl windows will get foggy, milky foggy, if not allowed to dry out completely, then all you have to do is lay it out in the sun until it clears.
Foggy monofilm is usually water spots and scratches, so a protectant should work after you clean it real good, but you'll have to reapply it on occasion, Rain-X also works, for awhile.

Try some Vuplex. They recommend it for clear panels on boat canopies. Makes the sail shiny and new again. Always be careful though, because some substances may prove detrimental in the long term. For example, Brasso does a wonderful job polishing Perspex, but eventually the solvents in Brasso will cause crazing in the plastic.