1) Why would Penske want to burden himself with that sort of overhead when he can just rebadge cars?
2) Assuming he DID take on that much debt, develop R&D, develop design assets, build a huge physical and human infrastructure, why would he want to do so in union states?
I would bet that if the Penske program works using first Saturn's waning production schedule and then Renault for inventory, he will sell the network to Renault and walk away with a BUCKET full of cash. Forget all the emotion - think of the financial aspects and potential.