"Cash for clunkers," the program formally known as the Car Allowance Rebate System (CARS), was an economic stimulus program that took place for one month starting in July 2009. Its aim was simple: to encourage people who drove older cars with poor gas mileage and high emissions (clunkers) to trade them in for more fuel-efficient models. The program surpassed its initial allotment of $1 billion well before the program was scheduled to end. Congress approved an additional $2 billion, and almost 700,000 cars were traded in, improving gas mileage by an overall 58 percent. Roll on to see the 10 most popular cars purchased by former clunker owners. (Text: Ashley Chase/MNN)