Academic

I would really like to read some good reporting on why GM is unwilling to sell Saab.  At first blush, it seems odd; wouldn't G.M. be better off selling at any price than incurring the costs of shutting Saab down?  What is it about GM's diligence on the Russian-backed Spyker that cause the deal to fall apart?  Concern about protecting GM intellectual property?  It is pretty unusual for a seller's diligence on a buyer to scuttle a deal. 

Other possible explanations -- buyers are looking for GM to finance the acquisition or assume various Saab liabilities.  Or are tax implications playing a role?