If you have an old ping-pong ball or an extra piece of Styrofoam lying around the house you can easily make a bat antenna ball that you can use to decorate your car. The process is quite simple, just paint the ball black and add facial details like wiggly eyes, fangs and ears. You can create the wings from pieces of black trash bag plastic or felt. You will want to make sure that you attach the wings to the ball securely so that your bat will be able to withstand the wind and speed that it will be subject to. It is a good idea to first adhere the wings to something sturdy, like a piece of metal and then use glue to secure its position in the foam ball.