The Rover will have 6 powered wheels, each driven by a 12 volt 230 watt Peg Perego Gearbox Motor assembly I got from http://www.kidswheels.com. Also got the wheels (Peg Perego Volkswagen Majica Wheels) and hubs to attach the wheels to the gearboxes from KidsWheels.com. The advantage of buying these way is the everything fits together withoug any kludges. The disadvantage of using 6 individually powered wheels is there is no neutral so if a motor assembly fails the Rover is dragging a wheel and pushing the Rover around is tough. Also we've decided not to have any steerable wheels at this point. Steering will be done by driving the wheels at different speeds and directions like a tank.