That clunker in your garage could be worth $4,500.

The new federal Car Allowance Rebate System rolls out this week in a financial stimulus package designed to help you, automakers and the planet.

The idea is to sell more fuel efficient cars, get more gas guzzlers off the road and help offset the cost of a new car -- what's likely your second most expensive purchase after a home.

The program is managed by the U.S. Department of Transportation's National Highway Traffic Safety Administration (NHTSA)  and is effective for qualified purchases and leases made from July 1 to Nov. 1 2009 at approved dealerships.

CARS credits for your trade-in range from $3,500 to $4,500 toward the cost of a qualified new car or lease.

The trade-in must have been manufactured less than 25 years before the trade-in date and be continuously insured and registered to the same owner for the full year preceding the trade-in.

You'll need to bring to the dealer proof of insurance with the policy number, vehicle identification number (VIN) and start and end date of the coverage; proof of registration for the past year; a clear title free of any liens or other encumbrances; and the vehicle manufacturer date found on the driver's door or door jamb.

The vehicle must be drivable and have a combined city/highway fuel economy of 18 miles per gallon or less.

The new vehicle must get better mileage than the trade-in. How much better depends on the type of vehicle traded-in and purchased. The credit is $3,500 or $4,500, depending on the mileage improvement.

Except for providing qualifying documents there's no paperwork for you in the CARS program.

The car dealer applies the credit, reducing the price you pay at the time of your purchase or lease. The dealer obtains reimbursement from the government.

You'd better hurry. Money to fund the program could run out before November.

Illustration for cars only: 2009  Pasch Consulting Group, Inc. | CashForClunkersFacts.Com