The J3 Soapbox Car

(A soapbox car - also variously known as a soapbox cart, and billy cart - is a motorless vehicle capable of holding a driver, usually a child, built for the purpose of racing or recreation. Propelled by gravity, soapbox cars can reach upwards of 50 km/h. Originally, soapbox cars were built from wooden soap or orange crates and rollerskate wheels)