Last week, President Barack Obama signed what's been called the "Cash for Clunkers" program tacked on to a military spending bill.

The $1 billion program aims to sell more cars while improving fuel economy across the land.

It seems Congress couldn't get more excited about the Cash for Clunkers. The Senate passed it by a 91 to 5 vote, while the House issued a less-impressive, but still overwhelming, 298 to 119 margin.

In theory, getting gas guzzling cars off the road while helping boost the struggling automakers sounds like a fine idea. And it may actually work to some degree, but if anyone expects this to be a watershed moment for either the car industry or for the environment, think again.

Under the bill, those who trade an old vehicle for a shiny new one that sips gas can get $4,500 toward the purchase of the new car.

The program comes with so many requirements that few will be able to take advantage.

Here's an outline of some program requirements:

The trade-in car has to be less than 25 years old, be registered in the last year and get no more than an average of 18 miles per gallon.

The program applies only to buying new cars. The new car must get at least 22 mpg. For those trading in a car, the new car has to get at least 4 mpg better mileage than the trade-in for a $3,500 voucher. If the new car gets 10 mpg better fuel efficiency, the trade-in will be worth a $4,500 voucher.

Trucks, mini-vans and SUVs are subject to a different standard. If the new truck gets 2 mpg better fuel efficiency, the $3,500 voucher applies. The $4,500 voucher applies to trucks that improve mileage by 5 mpg.

Industry estimates the program will help sell 250,000 new cars and trucks. That's great, but industry insiders said Detroit needs to increase its sales by millions to buoy the carmakers' dire situations.

The program targets a fairly narrow market - those who want to buy a new car and are willing to accept no more than $4,500 for their trade.

The vouchers are in lieu of a trade-in, as the trade-in car is required to be destroyed under the law. So anyone with a car of decent value may find the program doesn't get them ahead at all.

For those who are able to qualify for the Cash for Clunkers program, good for you. Take advantage of it, save some cash and get out and enjoy your new vehicle.

But for us as taxpayers, Cash for Clunkers lands with a dull thud.