A vehicle body stiffener comprises an assembly of an outer member and an inner stiffener member which are joined to form a closure for the body. The inner stiffener member is formed to carry tension, compressive and torsional loads from the vehicle body and two locating pins at the corners of one side of the assembly and two latch pins at the corners of the opposite side of the assembly engage complementary receptacles on the vehicle body to make the assembly act as a structural member of the body to transfer forces from the body to the assembly. The assembly is preferably pivotally connected to the vehicle body by a pair of hinges which allow the assembly to be opened to gain access to the vehicle body interior. The assembly can be an engine compartment hood, a trunk lid or other closure.