The Plastic Window
The 1997 through 2002 Model 986 Boxsters had a large flexible single plastic rear window in their top. Model year 2003 saw the introduction of a much smaller glass window in a top with a very different frame. 2003-2004 frames and tops can be retrofitted onto 1997-2002 bodies with very little trouble. But the glass window is smaller than the plastic one. Less visibility. And GAHH makes a glass windowed top replacement that can be installed onto the 1997-2002 frame.
The plastic window can get cloudy and brittle over time and can crack:
* because they dry out (don't have any of the nutrients that evaporate from plastic in the heat put back in via some plastic care product like Novus #1)
* because they are opened/closed in cold weather which makes them brittle and more liable to crack especially if they haven't been kept supple
* because they aren't "chopped" (put top about half way down, get out of car and use the side of your arm to make sure the top is folding evenly across its entire width) and so fold in an uneven manner putting strain on the plastic window, then lower it the rest of the way.
But the top doesn't need to get cloudy or brittle.
My top is about 7 years old and is as clear and supple as the day it was put on perhaps 2 years before I bought the car. It is not the original top and doesn't fit as well as the top I had on my '99, thus requiring I be very careful to "chop" every time I lower the top. It receives regular preventative care which keeps it this way.
I think that the reason mine has lasted so long and looks so good is it has received regular maintenance with a product from a kit of products from a company called Novus. They produce a set of 3 treatments numbered #1, #2 and #3 sold in a kit. Think of them like grades of sandpaper. #3 would be the roughest. You use it when things are bad and you need to get the dulling film off the plastic because it has been neglected. Use #3 sparingly as it does take some of the top layer of the plastic away with it. I found I only needed to do it on the outside and then only once to cure the neglect that occurred before I bought the car. #2 you use to smooth the scratches left from the use of #3. I used #2 the first time on both the inside and outside of the plastic window. #1 is more like a polish, I use it on the inside and outside of the window once every 6 months. I use an old wash cloth to apply it, wait for it to dry and then use an old cotton t-shirt rag to polish it away. I use nothing fancy like a special polishing cloth.
And the result is a clear, flexible window. I attribute the increased flexibility to the #1 somehow restoring some of the chemicals in the plastic that prevent it from drying out.
You can find out more about the products I use to maintain my car at link. There is a whole grouping of top related web pages here.
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