As an alternative to a known partition between a passenger compartment and a luggage compartment of a passenger vehicle that is open at the top, a preassembly unit including a transverse member extending over the width of the vehicle and insertable into side receptacles fixedly mounted on the body is proposed. The transverse member is additionally supported via struts on the automotive body. The struts run obliquely downward and outward at an angle of approximately 45.degree. to the transverse member, resulting in a large clearance below the transverse member that can be utilized for loading between the passenger compartment and the luggage compartment.