Powered by a blast of air, these little racers can really move, making a clean getaway as soon as you set them down! Kids can assemble a bunch, then host their own mini derby.
For each racer, decorate a soap box with colored-tape racing stripes and stick-on numbers.
Use the pencil tip to poke 2 axle holes on each side of the box, 3/4 inch from each end and 1/4 inch up from the bottom. Push a skewer section through each set of holes.
For wheels, glue beads onto the ends of the axles, then let the glue dry.
Blow up the balloon a couple of times to stretch it out, and stick the bendy end of the straw into the neck.

Use tape to seal the balloon to the straw, then tape the straw to the top of the box. To set your vehicle in motion, inflate the balloon through the straw, then pinch the end, set the car on a hard surface, and let it go.