This is how the Government decided to kill off cars being turned in for the Cash for Clunkers program:
Personally, I think this is a waste. Many bad cars are going to continue to run the roads, while many still decent cars get the treatment you see above. Me, I still have my 1994 BMW 325i and given that the car does not qualify for the treatment above (not that I would permit such a thing to happen to it) if I decide to replace it, it will most likely be with a newer-used car.
Anyway, why does this program require you to but a new car? Why require the purchase of any car at all? If a person were to turn in their old gas-guzzler and pocket the money instead of buy any car, isn't that even better for the environment? (You can have some requirement that they not purchase any car for a year or forfeit the cash.) Just saying.