Under the hood of "Cash for Clunkers"

On Capitol Hill, there's growing momentum for legislation called "Cash for Clunkers." In fact, there are several bills circulating in Congress and the details are in flux. But the general idea is to use tax dollars to encourage people to trade their old gas guzzling clunker for a new fuel efficient car. The hope is to help the slumping auto industry and the environment at the same time. Tamara Keith gives the environmental claims a test drive.