for the sake of brevity, if you owned a car that fell into the parameters-- 25yrs old or less and got crappy mileage-- you could trade it in to a dealer and get a tax credit toward a new leased vehicle.
there were a bunch of caveats like the car had to registered and in driveable condition, and depending on how much better mileage the new car got than what you were trading in dictated how much money you got toward the new one. however, one of the key elements was that it had to be a new leased car-- they didn't just give you cash for your car.
