Just like new car buyers, U.S. lawmakers have another version of the "Cash for Clunkers" legislation to test drive and kick its tires.

U.S. Sens. Dianne Feinstein (D., Calif.), Susan Collins (R., Maine) and Charles Schumer (D., N.Y.) have unveiled an alternative to the proposed "Cash for Clunkers" legislation now in gear in the House of Representatives.

The Senate proposal would require that the newly...