If you think about it, until a child learns to walk, life has a different meaning. Before walking, the child is wholly dependent on a parent for everything. Once a toddler is able to maneuver without anyone's help, it makes sense that the child will identify with and view other moving things with great fascination, especially if they make a loud and interesting noise.
In that spirit, this article’s reviewed books are for all the toddlers who love things that move. There will be a natural gravitation and interest in books that carry this theme.