The Saab 900 79-94 Convertible top is in two pieces. If the glass does not need to be replaced then you will only have to replace the front half. If the glass needs to be replaced you will have to replace the glass and material which surrounds it. Most people think that the top is one complete unit but it is not. You can remove the front 3/4 section of the top and when you do you will expose the glass in the rear half top section which shows that that are separate.