I was proposing the one traded in and the one bought
that if getting rid of gas guzzlers was the goal, there should have been a minimum percentage of increase in the official mpg of the new car.
Say 25% as an example.
Old car gets 12 mpg, you'd have to trade it in on one that got at least 15 mpg.
Old car gets 20 mpg new one would have to get at least 25.
If you just wanted to boost car sales, you wouldn't have mpg ratings involved, just every care over xx years old would be eligible. There was a provision you had to have own the car and licensed it for at least a year so you couldn't buy a clunker and then trade it in.
The provision that the car had to be worth less than $4500 seems a bit unnecessary, why would anyone trade a car in for less than it's value? Of course book value at the time of the cash for clunker deals might have been hard to get, since everyone was holding back so much right then anyway waiting to see what was coming.