Brasso`d my grotty windows today . Went from looking like a well used ice rink with a smoky finish to a still scratched but very clear finish . They will do until I can find a good second hand front centre .
For general cleaning I use care a van plastic window cleaner.
I would never use mr muscle or anything strong like that because I would worry it would make the plastic brittle.
As for scratching ...
I used to be so careful with mine but it don't make any difference how careful you are... a couple of trips to the dealer and all your efforts go out the window because I don't think when they wash the van they are as careful as we are.
For scratched windows try Fenwicks Windowize. Available in many Halfords as well as many places online. Small tube but only need a very small amount, lasts for ages. Works just as well on awning window panels too!
Never ever rub a perspex window without rinsing it thoroughly with some kind of liquid, be it water or a glass cleaning solution.Its the microscopic scratches you cant see that build up a bit like the swirls on the car thats polished every week. plus of course if you dont rinse off the slightly bigger will scratch as you carefully rub them in arrrgggghhh!
Im no expert on the chemical content of them but the metal polish/paintwork type abrasives may have chemicals in them that will affect perspex in the long run, certainly some have petroleum distillates in them which are very bad for perspex.
Greygates does not have any nasties in it, its a cleaner and mildly abrasive it was originally used on aircraft perspex windows so its cv is good and if used with a decent microfibre cloth will produce excellent results. I know ive spent hours on aircraft windows doing just this job............had arm muscles like a weight lifter lol.
Only one word of warning the ebay sellers advice is not entirely clear. You do need to rub hard with it like Tcut not just rub on and leave to dry. Once you think youre done, then leave it to dry (goes hazy or white depending on how much is on) then clean off much like dried car polish.