DENVER -- The “Cash for Clunkers” program is expected to help spur the purchase of 250,000 new automobiles.

One of the goals of the program is to stimulate the economy. Another is to lessen America's dependence on foreign oil by providing incentives for the purchase of more fuel efficient automobiles.

But what happens to the "gas hogs" that are traded in?

Industry officials tell 7NEWS that those trade-ins will be kept off the street.

"The frame and the engine ultimately have to be crushed," said Tim Jackson, of the Colorado Automobile Dealers Association. "The dealer has certain obligations, such as disabling the engine before it leaves the dealership."

Most will be disabled with a compound called sodium silicate.

“They remove the oil from the vehicle, put the plugs back in, then pour in sodium silicate for a few minutes and it locks up,” said Alice Corns of Colorado Auto & Parts Recycling in Sheridan.

Corns said the engines will then be crushed.

She said the transmissions and drive shafts have to be split up and can be sold separately.

“The rest of the car can be used for spare parts,” Corns added. “What’s not sold within six months has to be crushed.”

Once the cars are crushed, they are then sent to a shredder, which chops the metal into pieces the size of a fist.

“Those metal pieces can go to a mill in Pueblo, or could get shipped to China,” Corns said. “It depends on what the markets demands are.”

Corns spent Tuesday afternoon taking part in a web seminar to learn more about the auto recycler’s role in the “Cash for Clunkers” program.

She said she doesn’t necessarily agree with the program, but understands the needs for restrictions.

“If they don’t do something at the point of the dealer, potentially a salvage auction could get a hold of it. They could resell it on a bill of sale, even though it’s not supposed to happen, and it could end up in some other country,” Corns said.

Corns added that all “Cash for Clunkers” trade-ins must be processed by an authorized licensed auto recycler or scrap processor.

She said Colorado Auto & Parts is a licensed recycler/dismantler that participates in the National Mercury Switch Removal program.

She said some of the cars being traded in still have mercury switches.

“There’s one gram of mercury in a mercury switch,” Corns said. “And one gram of mercury can contaminate a 20-acre lake.”

Jackson said the “Cash for Clunkers” program, officially known as the Car Allowance Rebate System appears to be working.

He said new car sales were up about 12 percent in Colorado over the weekend.

When asked the definition of a clunker, Jackson said that for this program the vehicle must be a 1984 model or newer in driveable condition.

He said the car must have been licensed, registered and insured for the last year, and it must have a fuel efficiency rating of less than 18 miles per gallon.

Congress has appropriated $1 billion for the program… which is slated to expire Nov. 1.

But Jackson doesn’t expect the money will last that long.

“It could run out in the next two, three or four weeks,” Jackson said. “So if you have a clunker that you want to turn in on the CARS program and get credited $3,500 to $4,500 against a new fuel efficient car, do it today or this week or next. Don’t delay.”