Sara and Lola test their wind-up. If it doesn't go, it often helps if you wind it more. Lola explains that if the two wheels are the same it will go straight. If you want it to go in circles, make the wheels of different sizes.
Experiment with your wind-up. Make changes in the size of the wheels. Try different lengths and thickness of rubber band. If you wind it more, will it go further? How much further?