Automakers would like to just cast their car chassis and bodies instead of stamping and welding sheet metal.
Aluminum is finding some use for the same reason.

So Are PVC molded cars the future?
Despite higher initial material costs compared to steel, they would be offset by less tooling and higher flexibility for model changes.

Using contrarian principles, GM is refusing to use PVC in their cars, although only in interiors.
GM and most US automakers are known for their bad decisions so it makes sense that if they refuse something then that's a good thing and they will try to catch up when it's too late ...again.
http://lists.essential.org/dioxin-l/msg01081.html
Of course PVC pollution can be overcome.