My soap box was deep red with an off center yellow stripe although you can’t tell that from this B&W photo. My brother, Mark’s, car was yellow like the Cheerios box, his favorite breakfast cereal, and my father helped us build our soap boxes.
The rules were kind of fuzzy on parental involvement and some parents went so far as to illegally weight the front end or rework the bearings in the wheels to give their kids an edge. My dad played by the rules but I’m quite certain we were too spaced out to be much help. At the same time, my younger brother, Fran, could have built a motorized vehicle. My dad has been doing some downsizing and he gave me this photo from the Times Union, a sponsor of the 1964 Soap Box Derby.