[Spinnaker]

There is a product called VLP Vinyl Repair that you can get at the hardware store that will seal up the tear.
To restore the clearness there are lots of products on the market that everyone uses. Do a search in the forum for plastic rear windows.
I use the Porsche Polyglass Polish, and Plexus to maintain my plastic rear window.
It will take a lot of work to get an abused plastic window looking clear again. Keep it that way by never wiping or cleaning it dry. Every time you touch it with anything, it will scratch it. Even running your finger across it will scratch it. To clean the window, I use the hose to blast off as much of the dirt as possible with water. Then I use a soapy clean sponge to gently wipe the window clean, followed by a rinse with the hose. I remove the water drops with a synthetic chamois. Remember, anytime you touch the window with anything, it will scratch it. The plastic is so soft there is no way to avoid it.
A dirty clear window is better than a clean scratched up and hazy window. The trick is to minimize the damage when you clean it, and to bring it back the clearness with the polishing products. Plexus has UV inhibitors and plastisizers in it to help keep the plastic from getting brittle and yellow.
If your top is in good condition, another way to go is to get a new window sewn in, then you can start out from square one with a clear window.