This invention has as its object to efficiently and effectively plan a vehicle. To accomplish this, this invention has an exterior model building program (63) for building an exterior model having information associated with the exterior of a vehicle, a reference model building program (64) for building a reference model having information associated with reference components of the vehicle, and information associated with the sitting positions and postures of passengers, and a display program (65) for superimposing the built exterior model and reference model on the basis of a predetermined rule.