A modular system is provided for producing motor vehicles having at least first and second vehicle variants that differ from one another by having different space requirements in an accessories compartment that is separated from a luggage compartment by a partition wall. The system has a first partition wall that is secured to a side of an upper crossmember facing the accessories compartment to produce a small accessories compartment on the first vehicle variant. The system also has a second partition wall that is secured to a side of the upper crossmember facing the luggage compartment to produce a large accessories compartment on the second vehicle variant