Making a mousetrap powered car in my engineering class. I have already decided the Drivetrain (an unconventional Rear engine, front wheel drive setup), and I will probably use an arm attachment to extend the mousetrap. I just need to figure out what I'm going to use as wheels, a chassis, and the axles. I was thinking CD's or K-nex for wheels, but I'm leaning towards CD's. Plastic or light wood would be ideal for the chassis, but I'm trying to think a little outside the box.