On the other hand, investing in a newer car also has its benefits. It means that consumers will spend less money on replacing and maintaining their cars, at least temporarily, and reduce the burden aging cars puts on people. It gets more people into newer cars. It will also mean that these people pay less on gas. Right now, reducing the burden on the consumer is the best program. And they're also safer, and you could argue that this program could even indirectly save lives (no I would never go "cash for clunkers saves lives, it's a good program!" but it's a fact that new cars are safer). And sure it may create a "car bubble" but the fact is is that there never would've been car sales to create this bubble in the first place without this program. The benefits outweigh the drawbacks.
I don't really support it because of the environmental benefits, I support it because of the benefits it gives to consumers. It reduces the costs that aging cars with low gas mileage put on the consumer. The environmental impact is a relatively minor benefit - I wouldn't really consider myself too much of an environmentalist.
Maybe the program isn't a game-changer, but any amount of progress is good progress. Unfortunately doubters will declare it a failure because it's the kind of program whose full benefits cannot be directly measured and whose drawbacks are more readily apparent. The negatives are always easier to focus on than the positives.
The only thing I disagree with is that I think the cars should be allowed to be sold, but this isn't enough of a drawback to make me withdraw my support.
Except that the government ran out of money, the government has not been keeping up with dealers' requests to be compensated and dealers are hesitant to extend the deal to consumers, prices for used cars will go up since the clunker cars have to be scrapped by law, engine parts from clunkers cannot be sold so fixing older cars that people cannot afford to replace will be more expensive, the carbon footprint of making a car to replace a clunker will usually take 5 to 10 years to offset, no stimulus is really happening since this is a transfer of money instead of wealth creation, and this program is creating an auto bubble that will result in a decrease in the purchases of cars for the next 1-3 years. Other than that, though... :|