Drive it. Seriously. Driving an old gas guzzler 50,000 miles has less impact on the environment than building a new car.
Of course some of these "old gas guzzlers" being destroyed by the CARS program might have got as good or better fuel economy than a new car. Didn't the VW diesels of the mid-80s get 60+ MPG? Where can I buy a new car today that gets 60+ MPG?
CARS: Just another corporate welfare program.