Why? A company could always have ordered a new small batch of molded parts, and machine shops exist to build whatever plans you give them, or just take the worn or broken part and make a not broken part to match.

Moreover, most of the parts on a vehicle like this are going to be metal shafts, gears, barrings, ir panels, upholstery, etc… Not the small, highly intricate parts 3D printing excels at.