A partition panel extends in a first direction to partition a passenger room from a trunk room in the rear portion of the car body and is provided with an opening. A floor panel extends in a second direction which is different from the first direction. Upper attaching portions respectively arranged in a pair of right and left upper end portions of an X-shaped reinforcing bar are fixed to upper attached portions formed on the partition panel. Lower attaching portions respectively arranged in a pair of right and left lower end portions of the reinforcing bar are fixed to lower attached portions formed on the floor panel.