Removing the yellowing on the plastic rear window?
 

I just bought a 2000 Boxster and it is in pretty good shape, but the rear window is entirely yellowed, to the point that you simply cannot see out a sizeable portion of the window. It's practically useless as a window at this point. I'm wondering if anyone has managed to treat the rear window with anything so that it can become at least a little clear.

I've thought about simply replacing the top, but the canvas is in very good condition, so it seems rather wasteful when the window is the only issue.

http://986forum.com/forums/uploads02...1689890917.jpg
The liquid on the window is simply water from rain a little bit before I took the picture.

It seems like maybe the previous owner tried to clean it with something that may have damaged the plastic, unless those are common places for wear. Is there any way to get the window a little functional or replace only the window?

Don't have any ideas for cleaning. or treating it, but the prior owner of my car had the window replaced. From what I understand the plastic window itself is fairly cheap (around $30), but the window is sewn in which is pricy, but cheaper than a new top.

Novus has fine plastic polish products. Polishing the inside will be the hard part. I would use their # 2 then #1 on it. You will be surprised how it cleans up. Be aware if you fling polish in your fabric its a real pain to clean off.

I would consider this.
 

Does anyone know of a source to replace the plastic in the Phoenix, AZ locale?

Using Novus fine plastic polish products is a great way to restore items, similar to how a refurbished iPhone can be revitalized to look and function like new. Just be cautious about getting polish on fabric—it can be tough to clean! Always apply carefully for the best results.