Abstract: A vehicle body structure which can provide a wider passenger compartment than conventional sedan-type vehicles. The vehicle has a substantially flat floor which provides extra space and a single integral door opening on each side. The door opening is closed by a front swinging door and a rear sliding door. The rear sliding door support mechanism is adapted to allow the floor to be positioned lower than in conventional van-type vehicles. The front swinging door has upper and lower door lock mechanisms for locking the front door when closed. The rear sliding door support mechanism includes upper and lower guide rails which are respectively adapted to reinforce a roof side rail and a side sill comprising part of a vehicle framework to provide sufficient resistance to bending stresses applied to the framework, thus allowing a center-pillarless body structure.