I think a brilliant joint venture would be Penske and Magna International buying Saturn and GM Europe.
Really, what should have happened with this bailout is the government should have made GM declare bankruptcy and split into General Motors North America and General Motors International.
They could operate as a joint venture for development, GM International could be owned by Penske, Magna, shareholders, etc. and only operate the Saturn brand in the US. There could be shared engineering in some products for things such as powertains, but they would sell the GM International product line.
GM North America would be the Chevrolet/Buick/GMC/Cadillac lines and dealerships, and handle the US, Canada and Mexico manufacturing and sales operation.
GM International would probably operate as a seperate entity financially and scrape by, and GM North America would declare bankruptcy to restructure.
Give the pension fund a chunk of the company, renegotiate present contracts, cut where needs to be cut and if the government truly had to bail them out, take the money, re-negotiate the pension liabilities to a fair level where nobody starves to death but it is reasonable, and give GMNA a line of credit to cover that at a low rate ongoing until the liabilities are retired.