I got my kid a go-kart and wasn't overly explicit about where he should and should not ride it. On one particular day, he cut between the house and the garden, and snapped the 4" PVC over the septic tank off below grade. I saw him run through the area, and saw the foot long piece of pipe tumbling after the kart. He never stopped and later claimed he never saw it and knew nothing of it. I spent a little time later that day restoring the pipe back to its original condition, then telling my son not to ride the kart between the house and the garden.
So, I'm going to recommend you use a kid on a go-kart. Not sure how you'd go about capping it. It will be a pretty rough "cut."