a vehicle body structure is described that includes a pair of rear rails , a bumper beam and a spare tire compartment including a spare tire . the rear rails have a rear segment aligned with the bumper beam , a middle segment disposed above the rear segment and a front segment that extends downwardly from the middle segment . after a 50 mph 70 % movable deformable barrier rear impact test , the spare tire compartment including the spare tire hinges downwardly to create added crush space and the middle section is raised upwardly to reduce the extent of intrusions into the passenger compartment .