Ignore for a moment the fact that Detroit may not have a design ready to satisfy the following plan. Ignore also the time it would take to retool their plants. What appeals about this idea is the combination of aid to the auto industry that is coupled to a more innovative agenda than simply enabling them to continue failing in the same manner they have been for decades.
The US government should order a complete replacement for its vehicle fleet to be delivered over the next four years. The new vehicles must be either plugin electric hybrid, pure electric, or possibly natural gas. Obviously retooling both at the manufacturers and suppliers is required to deliver this order so the government should be willing to prepay a significant part of it as it does for new weapons systems. That gets money into the system fast and creates/saves jobs almost immediately.