In message , GO
writes
Thanks, my windows are probably the same type of material (tougher than
perspex) I shall have a go in an inconspicuous area, I could email the
manufacturers for some advice.......


If they're polycarbonate you need to ask the manufacturer, IIRC
polycarbonate does some funny things when certain chemicals are used on
it, I.E. it becomes very brittle whilst showing little sign of damage.
Definitely worth the cost of a 'phone call/email IMHO.
--
Clint Sharp