Today's question: How effective was the 'cash for clunkers' program?

The "cash for clunkers" program was the focus of much of the debate about the stimulus package.

Officially known as the Car Allowance Rebate System, the program gave people a rebate of a few thousand dollars to get rid of old cars in favor of newer, gas-efficient models. Congress found the program to be so effective that it extended the appropriations from $1 billion to $3 billion.

Car dealerships in Columbia found the program increased car sales — but they also said the rules could be confusing and difficult to navigate. One dealer had only been reimbursed for 25 of his 375 sales.

Proponents cited the 457,000-plus transactions and the increase in car sales. But some say the boom now means a decrease in car sales later. And many people have criticized the amount of government spending in the stimulus package as a whole.

Sen. Claire McCaskill, D-Mo., and Rep. Blaine Luetkemeyer, R-Mo., voted no on extending the program. Sen. Kit Bond, a Missouri Republican, voted yes.

How effective was the Cash for Clunkers program? What lessons should lawmakers take away from this for other stimulus programs?