Design of modern vehicles requires to consider security related norms (SAE J3061, ISO 21434) and the implementation of security related design patterns. This includes e.g.
Consideration of security risks early on and at key development stages (mostly those with design decisions)
Identification and addressing of potential threats and attack targets
Appropriate methods of attack surface reduction
Layered cybersecurity defenses (defense-in-depth)
Identification of trust boundaries
Inclusion of security design reviews in development process