President Barack Obama's Cash-for-Clunkers bill that eventually was turned into law last month could eventually be extended if the current program is considered successful, according to auto industry insiders.

The basis of the program, which was signed into law on June 24, aims to have car owners in the United States trade in their clunkers -- a 25-year car age limit is in place -- in return they'll get cash towards a new, fuel-efficient car.  Essentially, gas guzzlers will be taken off the roads and more fuel-efficient cars will be sold, which will help reduce pollution and stimulate the auto industry.

The program now has an expected $1 billion in funding, which will be good for only 250,000 vehicles, which isn't enough according to Dave McCurdy, Alliance of Automobile Manufacturers.

"I think it'll go very quickly, and Congress may have to revisit it in the fall," McCurdy said during an interview with Automotive News.  "We think there'll be additional phases of this.  It'll probably evolve."

McCurdy clarified his stance by stating the program won't get an extension depending on the type of vehicles shoppers are purchasing.  A person purchasing a new truck qualifies for a $3,500 cash-back government credit assuming the truck has at least a 2 mpg improvement in city/highway fuel-economy than the vehicle being traded in.  It's possible a $4,500 credit will be issued if higher fuel efficiency standards are met.

A new car being purchased must be at least 4 mpg higher than the car being traded in, with a $4,500 credit also offered if the new car is at least 10 mpg more efficient than the old car.

There is some concern that car owners won't be interested in trading in their cars if 4 mpg is the standard, while it's possible many people may just go out and purchase new trucks.  If consumers are purchasing more trucks than cars, then Congress may elect to not renew the program this fall.

The program officially begins on July 24, but it appears a select group of car dealerships may be experimenting with the program.  Dealerships who are caught jumping the gun, however, face stiff fines up to $15,000 for each infraction, the U.S. Transportation Department said in a statement to auto dealers.

In a separate report, the government is warning interested consumers that they should verify the Web site they're looking at is a legitimate Cash-for-Clunkers site.  Scammers have already started using the likely popular car trade-in program to cash in by getting people to turn over their Social Security number and other personal information.