Why does a dashboard crack?
What is that brown haze inside new car windshields?
What is that "new car smell"?

The answer to all the above ............ Plasticizers.

A plasticizer is a chemical added to plastics to soften it. For old 924 and early 944 dashboards, there is a urethane foam layer covered by a thin vinyl surface. This vinyl surface is PVC (polyvinyl chloride) and is the same material as PVC water pipe. Yet, it is soft? The plasticizer makes the vinyl soft. Over a period of time, the plasticizer evaporates and the soft vinyl surface becomes brittle and cracks.