I am kind of wondering if this entire program has enough conditions on it to make it more of a PR stunt than anything else. To take advantage of it, you need something defined as a "clunker". Who would own such vehicles? Mostly people who can't afford to replace them. And offering people 4500$ isn't going to be enough for them to be able to afford a new vehicle - if they were to replace the clunker, they would likely replace it with a somewhat newer clunker.

The one exception is that some people might keep an old pickup for those occasions where you need to haul some stuff. But for these cases, I don't see that there is a huge incentive to trade the thing in. You have an old vehicle that is paid for, and you want to have to start making payments so you have a shiny pickup to start hauling crap once a month? That doesn't add up either..

Exception #2: Someone who's kid is driving an old clunker, and they take this opportunity to trade in the clunker, buy a new car, and hand down the parents current car to the kid.

In other words, it's aimed at me. In the long run though, it's not likely to be cost effective for me to trade in a 1987 Mercury Grand Marquis to buy even an efficient car like a Honda Civic, and pass down my 2001 Chevy Prizm (Corolla clone) to my son. While he's still in college, my son only puts 3000-4000 miles a year on his car, so the cost of fuel isn't that big a factor. The cost of repairs on the clunker is a factor, but it would never be a big enough factor to be worth spending $14,000 on a new car to eliminate.

Don't forget the annual registration fee on the vehicle. In my state, Arizona, it is based on the list price of the automobile and the number of years since the vehicle was first registered. In short, the annual registration for an old clunker is about $15 / year and for a new car, it is several hundred dollars per year.