Chelsea is finishing her balloon race car.  To make one, you take a straw and attach it to a balloon.  Rubberbands work well for this.  Then you need some kind of axle and wheels, and maybe a box or a cup for the body.  Attach the balloon/straw combo to the top of the vehicle.  The end of the straw must be facing backward (it's the exhaust pipe, I guess), blow the balloon up set her down and see what happens.   Lots of tape and design redo's later, the car hopefully improves it's speed and distance.  We had everything from mini muscle cars, to cup cars, to Chelse's which was an axle only.  Thanks for the photo, Chelsea.  E