What vehicle was introduced in 1998 by Daimler AG as a City car which battery electric variant's field testing started in London in 2007?
Smart electric drive: The Smart Fortwo electric drive, or smart ed, is a battery electric vehicle variant of the Smart Fortwo city car, formerly marketed as the Smart Fortwo EV. Smart electric drive:  Field testing began in London with 100 units in 2007. Smart Fortwo: The Smart Fortwo is a rear-engine, rear-wheel-drive, 2-seater hatchback Microcar(or City car) manufactured and marketed by the Smart division of Daimler AG, introduced in 1998, now in its third generation.
Smart Fortwo