The AI-driven evolution of automobiles, exemplified by autonomous driving and software-defined vehicles (SDVs), is accelerating the integration of AI electronic components, including domain controllers, power electronics, and sensor fusion modules. Consequently, housing materials must simultaneously exhibit effective thermal management, mechanical reliability, lightweight characteristics, and compatibility with electromagnetic environments. In this study, these critical requirements are defined, and the design of polymer composites capable of multifunctional property integration is investigated. The application of carbon-based fillers with distinct morphologies reveals the inherent limitations of single-filler designs, while the resulting filler network structures indicate potential pathways for enhanced electromagnetic functionality.