Needless to say that would have a huge impact on our economy especially specific local economies that have factories from FM and Chrysler. Remember in addition to the auto plants themselves, there's thousands of part suppliers and others who rely heavily on the auto industry.
Also keep in mind that there's small business owners who own restaurants, gas station food marts etc located centrally that cater to auto workers and they will suffer greatly as well.
You should be able to get parts for them for 5 years, or buy parts from Hemmings.
But I think it's still highly debatable that the company will go out of business entirely... I'm guessing stock buyout with Ford... Chrysler has some good patents, and good designs.