recommended cleaner for plastic rear window "haze"

Hello Folks. Have gotten good help here before so wanted to post again. I have an older Boxster with the plastic rear window. It is so hazy, I can barely see through it. Once many years ago I found something to clean it (so know it can be done) but have lost track. What do you recommend to easily (and safely) clean it?

Thanks!

Plexus is the right advice. The other advice is to clean dust off the plastic before lowering. I only need to use Plexus on my OEM '02 window once in a great while and the window is clear.
Try this-take a wet paper towel and wipe the plastic (you'll be surprised at how much dust can get on that window). Then pat (not wipe) with dry paper towels.
This dust is a problem because when the top is lowered the material folds over with the dirty outside of the plastic rubbing against itself and the dust is an abrasive.
Good luck, Tom

If you have a marine/boat store near you, they should sell Plexus.

Novus makes a series of products designed to deal with the problem (if you already have it) and to prevent it in the future. The Novus 1, 2 and 3 products consist of bottles of plastic cleaners in decreasing levels of abrasiveness. The three products are sold in a kit with several microfibre polishing cloths for about $25.

If the top is new, only use #1. But if the top is already discolored, you start with the most abrasive cleaner, Novus #3, and a clean rag (I use a cotton washcloth) and you rub it on the surface as if you are polishing the window. Do the outside of the window first, then do the inside. Keep it off the top (but if it gets on, just wipe it off quickly). Let it sit for a while. And then take another clean rag and polish it off. Then do the same using the mildly abrasive #2. And finish up with the non-abrasive #1 which is more of a polish than a cleaner. You should only have to do this once.

In addition to cleaning and polishing the surface of the window, these products seem to put some sort of oil into the plastic that allows them to increase their flexibility and thus resistance to cracking.

For maintenance, I use Novus #1 about once or twice a year, though in truth my car doesn't sit out in the elements much with the top up.