Navistar just had another
Navistar just had another blow earlier this month when a federal panel of judges ruled against the EPA's exception given to the company to allow Navistar to continue producing non-compliant Maxxforce engines. When Navistar's emissions credits run out (which they are about to), they'll be forced to shut down production unless they've got a compliant engine to continue with.
If anyone buys a stake in Navistar, they'll have to figure out how to get the Maxxforce online or how to refit all of the proprietary vehicles to begin using another, compliant engine.
The 3-judge panel specifically said that the economic situation of Navistar is not of concern to the EPA and should not have been a reason for the exemption. Things aren't looking good for that company right now.