Modern vehicles are equipped with hundreds of ECUs deployed across vehicle networks. Each ECU runs a variety of safety and cyber-critical workloads which is facing an increasingly challenging cybersecurity climate, which is being driven by various factors such as vehicle system complexity, software complexity, supply chain complexity and an increase in wireless interfaces. With these challenges, the automotive sector is a perfect domain for the use of Security-by-Design and secure hardware technologies. In this paper, we demonstrate the application of Security-by-Design and the secure hardware Morello, one of the CHERI implementations, in the design and implementation of Telematic Control Units (TCU), a crucial component of modern vehicles. This results in a generic secure TCU design with well-justified security requirements and an understanding of the risks associated with it. As such, this work paves the way for the systematic integration of secure hardware for cyber-physical systems, of which automotive is just one application.