I have used some of the Aurora cleaning products and I have been satisfied. They make a product called Clean View that is specially made for clear plastics. I have no personal knowledge of how well the product works, but they do have a satisfaction guarantee. You might want to give it a try.
http://www.auroramarine.com/
From their website, "Ask the Skipper":
"Many thousands of boat owners have had fantastic success with Aurora Clear View. It’s a two-part kit. Part one is a cleaner / restorer that removes fogging, yellowing, and minor scratching from Isinglass (clear vinyl), polycarbonate, and acrylic. In other words, from all see-through plastics. Part two is a protector that has UV inhibitors in it to protect against sun damage and is anti-static to repel dust and dirt. It also fills in minor scratches to restore optical clarity and replaces some of the dried out plasticizers to restore suppleness. ....
It goes on ...
A few tips on the care and maintenance of see through plastic:
1. When cleaning your Isinglass, polycarbonate or acrylic, rinse well with clear water and pat dry with a synthetic chamois or soft clean cloth.
2. Never wipe your windows, especially when dry or with a paper towel as this will scratch the surface.
3. Never fold Isinglass. The best way to store your curtains is to place a towel on the surface and roll it. Folding will result in cracking.
4. Only use cleaners, made especially for see through plastics. Never use household cleaners. Some household window cleaners can destroy your Isinglass in a mater of months.
5.
Never use furniture polish on Isinglass. They will tint your windows yellow or brown.
6. Apply Clear View #2 to your see through plastics every 4 to 6 weeks to protect against UV degradation and extend their life and optical clarity. Also protect your compass dome, instrument crystals at the same time.
7. Do not let your Isinglass windows rest against stainless steel or aluminum rails. The suns reflection will burn permanent marks into the windows. Invest in offset spacers or cotton covers for the rails.
8. During winter lay-up, remove your Isinglass windows and store them at home if possible.
Again, I do not mean to sound like an advertisement, but maybe there is some good info here.
My best to all
John
Swee Pea