I bought a locker a while back, like the kind you would find in the employee room of a closing bed bath and beyond. It didn’t quite fit as expected so we ended up just tying the back hatch as closed as it could with a single rope and took back roads the whole way home. I don’t think we went above 20mph for fear of the damage this giant steel box would cause if it fell out. Also got a tetanus shot the next day because I managed to rip my hand on its rusted foot. Good times, I love that locker