Congress is mulling a proposal to pay people to get rid of those old gas guzzlers sitting in their driveways. Under legislation introduced Wednesday in both the House and Senate and called the "Cash for Clunkers" program, drivers could get vouchers of up to $4,500 when they turn in their old fuel-inefficient vehicles for scrapping and buy vehicles that get good gas mileage. People could also turn in their old cars for vouchers that could be used to ride public buses and trains. The bill, said Sen. Dianne Feinstein, D-Calif., "would be an important part of helping getting America's struggling...