To build a solar powered car, gather two solar cells, alligator clip leads, rubber bands and a small electric motor. Also gather a cardboard milk carton, plastic bottle caps, stiff wires and straws.
Use the cardboard milk carton for the chassis of the car and the plastic bottle caps for the wheels. Use a nail to make small holes in the center of the wheels, making sure that the wire, which serves as the axle, fits snugly into the holes. Take an extra cap and cut off the sides, leaving the top part. Glue this to one of the wheels, and then mount the axles to the milk carton by taping straws to the underside of the carton and threading the axles through them.
Attach the motor shaft and small motor pulley together, and then determine where to place the motor by connecting the pulleys with a rubber band as the drive belt. Position the motor so that the band stretches slightly, and mount the motor with tape or glue between a frame of wood. Use clear tape to bring the two solar cells side-by-side, and connect them in a circuit with the alligator clip leads. The positive terminal of one cell must connect to the negative terminal of the other. Connect the rest of the terminals to the motor.
If the motor spins the opposite way, switch the leads, and once it's connected it correctly, tape the leads to keep the wire in place. Mount the solar cells on the milk carton in an area where they can collect the most sun. Take the car outside, connect the drive belt and let it go.