That actually is pretty staggering and it puts Ford at a real competitive disadvantage since they have no relief from claims at all and continue to have to budget for past, present and future litigation, much of which would go away for Chrysler and GM...of course as the one non-bankrupt, Ford has a certain marketing advantage which offsets that to some degree.
It is tough to sue the Federal government, but GM is still just a corporation in which the Government is the majority shareholder. It is simply a legal person like any other corporation, and subject to suit under the same conditions and procedural rules any other corporation in a Chapter 11 lives with, it does not share in the Government's sovereign immunity. GM may be government-(majority)-owned, but it is not a government agency.