American cars are important to the United States' sense of identity. When people buy American cars, they are supporting their fellow American brothers and sisters that have spent hours working on that car and getting it delivered to you. They are also iconic cars, like the Mustang or the Corvette.
Even though I do not agree with the bailout of US automakers, I have to say that US autos are very important to America's sense of identity. We have long associated places like Detroit (The Motor City) with American car companies. If these companies were not around it would affect America's identity.