Topology optimization is a valuable tool in structural design; however, simultaneous optimization of multiple materials with extremely disparate rigidity ---such as steel and structural adhesives in automotive bodies---remains a significant challenge. This study proposes a topology optimization method for automotive roof structures composed of such materials. The approach employs the solid isotropic material with penalization method. To enable large-scale analysis in a massively parallel environment, we adopted the CUBE framework based on the building cube method. The method was applied to an automotive roof model to maximize stiffness under simulated cargo loads. First, we compared the topology derived from optimizing both steel and adhesive regions with that of a steel-only optimization. The results confirmed that simultaneous optimization yields a steel layout comparable to the single-material case. Furthermore, we conducted multi-sequential optimization. We performed optimization for the following three cases: (1) simultaneous optimization of both materials, (2) sequential optimization of adhesive followed by steel, and (3) sequential optimization of steel followed by adhesive. The compliance and optimal shapes obtained using each starategy were compared and discussed.