When people make toy wagons, they start with big, flat pieces of metal. A machine presses each metal sheet into just the right shape to be the main part of the wagon. Other machines then trim off the extra metal around the outside edge of the wagon and smooth the rough edges.    Then, the wagons are hung on hooks and this spraying machine paints the outside of each one. Special robot painters spray the inside corners so that every part of the wagon is covered with red paint.    To make the wagon's wheels, they start with a giant roll of metal. The metal moves through a machine that cuts and molds it into the right shapes. A person then puts two wheel parts together and a machine presses them into a single wheel. The wheels go through the spray machine to be painted white. When the paint is dry, a machine attaches a rubber tire around each wheel.    Finally, it's time to put the wagon together. Each person assembles a different part and when the wagon is all put together, one person does a final check to make sure everything works just right. Then, it's ready to roll!