Score the fold lines on the body of the train car, including the folds indicated at the ends of the sides. Cut out the body of the train. Fold the sides sharply at the top and just slightly in the middle of the sides to give the sides a slight outward bulge. Roll the roof of the train against a round pencil or dowel to give it a slight curve.

Score and cut out the underside of the train. Fold the tabs back and glue inside the sides of the train one side at a time. Match the fold line on the tab to the lower fold of the train side, and the top of the tab to the upper fold of the train side.

Cut out the two ends of the train. Fold the triangular tabs back. Give the front of the train a slight curve to match the shape of the roof and floor of the train.

Glue the front and back ends to the body as marked, with the triangular tabs tucked inside the roof. Press the ends in place to fit snugly on top and bottom.

Cut out the wheel chassis of the train. Fold the ends down to assemble into a long box. Fold carefully to make sure the chassis is not twisted or crooked. Glue the wheels to the underside of the train.

Now your BART Train is finished!