A rear frame assembly is provided for use in an automotive vehicle extending between upright side walls to define a trunk opening. The rear frame assembly includes a cross car beam extending laterally between the side walls of the vehicle. A sail panel is fixedly secured to the cross car beam. The sail panel includes symmetrically opposite flanges adapted to conform to the side walls of the vehicle to define a path for diverting a flow of water around the trunk opening. The sail panel includes a conically shaped concavity for engaging a conical protrusion on the vehicle for locating the rear frame assembly within the vehicle during installation of the rear frame assembly to the vehicle.