Build frame for the model car
First of all you need to build frame of your model car. Take balsa wood and cut it to construct a frame which should be almost the same size as your solar panel. You need to join the pieces with glue.
Place axles in the frame
You need to drill holes near the end of your model car frame. Remember to drill near the narrow end in order to keep the holes in line.
Then place axles through these holes. You need to push them. Also keep in mind to place a gear on one of these axles.
Connect gear to the motor
You need to attach a gear to the motor and it should interlock with the gear on the axle.
Remember that you can attach a piece of wood by glue so that it can make a place for the motor.
After connecting the gear to motor, join the wheels to the model. You need to attach wheels in the end of the axles.
Connect solar panel into the motor
Next you need to connect the solar panels into the motor. You can do this with the help from wires. Remember that you need to join the positive terminal of solar panel to the negative terminal on the motor and vice versa.
You will know when the circuit is complete by looking at the tyres which will start moving after you make the connection.
After connecting solar panels into the motor with wires, you need to make the body of your model solar car. You can do this by cards or any other light weight materials.
Place the solar panels on the car
In the end, simply place the solar panels on your car. Position it where you can get maximum sunlight.
As the sunlight hits the car, it will start moving.