Private cars to the Supervisors of elections are fine, because the supervisor of the polling place goes accompanied by a poll watcher from each party. The ballot boxes have been locked, which was also witnessed by the poll watchers. Then they are delivered directly to the elections office - also witnessed by the poll watchers.
In this case, they were handed off to a rental truck and appear to have been witnessed by nobody. The rental truck then “delivered” them to the election headquarters. With no witnesses.
Don’t get too realistic or it won’t be a topic of discussion.