Do you mean the "gravity" car ride? We didn't call it that then, but it slowly rolled down a concrete track, made one or two turns and then at the bottom a pully/chain system took the now-empty train back up to the start. I remember the large, circular metal swings that you could sit four or more kids in, two by two facing each other. We learned that if somebody "pumped" the swing, by standing on the top seat/step of the swing, a brave kid could be launced high and far into the sand. What a thrill that was. As far as I know, nobody every got more seriously injured that "sand-strawberries".