How do you make a self propelled car?

Answer 1

you would take a tissue box and put wheels and a fulcrum and axle on it and then put a rubber band around it and roll up the rubber band and let loose then and it'll shoot away!!

This is wrong, if only slightly.

you take the mentioned tissue box, and put two sets of holes, right across from each other, on the long sides. then you take a piece of wood and cut in in half. Put one half in one row of holes, and the same with the other, on the opposite side. Put a piece of string around one of the woods and tie the other end to a third peice of wood. After this, you get some CD's and you attach them, to the wood ( I said attach to leave you with some creativity). make sure the string is at least 1- 2 feet long, and wrap it around the wood.. then attach the wood to a mouse trap flip bar on the inside of the tissue box. make sure the string is tight. as the mousetrap flexes to shut, the sting will unwind itself, causing the axle to turn, pushing the car forward!