Freshman year in HS.
i used wheels from a Hotwheels car, a 6" piece of 1/8" dowel rod, and enough balsa to hold the cartridge in the rear, and a small chunk in the front to hold 2 wheels, and super glued some pieces of a straw on the bottom for the fishing line, it was the fastest car....
that was till my buddy decided to just glue a straw to a catridge.
needless to say he had received a few days of detention because it almost took someones head off as it ricochet off lockers going down the hallway!!