Ferrite plates are essential elements in wireless power transmission systems. Their presence is critical to achieving adequate magnetic coupling and minimizing stray magnetic field. At the same time, reducing the volume of ferrite used in the vehicle assembly (VA) offers significant benefits in terms of cost and weight reduction. Topology optimization methods are particularly effective tools for applications like Wireless Power Transfer, where the magnetic field is not confined to a well-defined volume, unlike in classical electrical machines. In the present work, the Solid Isotropic Material with Penalization (SIMP) methodology is used to achieve an optimized reduced-volume design of the ferrite plate of a SAE-compliant VA that maintains magnetic interoperability with the starting design. The optimized plate was manufactured and its performance was experimentally validated and compared to the original VA. The results show that the fabricated plate is able to maintain a mutual inductance reduction of less than 10% with a 55% reduction in material volume, thus meeting the magnetic interoperability requirements outlined in the SAE J2954 standard. The impact of the material reduction on the system's losses was also evaluated, revealing that the proposed solution results in a 2% increase in losses when tested on a 3.3 kW test bench.