If the government bails out the majority of US auto makers (purchasing one in the process), and then enacted a federally funded incentive program (which is what CARS is) that only worked for US auto makers, there would be serious legal repercussions. Also remember than foreign auto makers have plants in the United States which employ US citizens. Not to mention the various testing facilities throughout the United States.
"The 300ZX Turbo is a dance; it's a song; it's rolling, roaring automotive art. There is no color that doesn't suit it. There is no mood-lifting chemical substance it can't replace." - Automobile Magazine