Edmunds.com has analyzed the car sales numbers during the Cash for Clunkers program and estimated that the marginal cost was $24,000 of our tax dollars for each new car sold:A total of 690,000 new vehicles were sold under the Cash for Clunkers program last summer, but only 125,000 of those were vehicles that would not have been sold anyway, according to an analysis released Wednesday by the automotive Web site Edmunds.com. ...The Cash for Clunkers program gave car buyers rebates of up to $4,500 if they traded in less fuel-efficient vehicles for...