Things You'll Need
Instructions
Set the wood block from the car kit in front of you. Midway down what will be the back of the car, drill a 1/4-inch hole at a 45-degree upward angle, so that the drill bit comes out at what will be the top of the car. Glue a metal washer around the entrance and the exit hole. Allow to dry.
Carve the block into the car shape that you wish.
Insert the axles into the front and rear of the block and attach the wheels. Some kits have pre-drilled holes for the axles. If yours does not, use the narrowest drill bit you have to drill out holes for the axles.
Use a cotton-tipped swab to push the balloon through the hole in the back of the car so that the body of the balloon is on top of the car while the aperture remains at the back. You will need a balloon that is long enough so that most of it hangs out of the top of the car. The aperture should be big enough that it does not slip through the hole you drilled.
Blow the balloon up through the back of the car. The balloon will swell into its natural shape atop the car. When you are finished, affix the clothes pin or hair clasp to the balloon aperture at the back of the car to keep the air from rushing out. Set the car wherever you want to send it, release the clothes pin or clasp and watch it go.