Although traditional automotive development has mainly focused on functional safety, as the number of automotive hacking cases has increased due to the growing Internet connectivity of vehicles, security is also becoming more important. Accordingly, international organizations are preparing regulations to ensure security on automotive development by emphasizing the concept of security-by-design. The problem, however, is that no specific methodology has been suggested. In this paper, we propose specific security-by-design methodology for automotive development based on standards related to security-by-design. With our methodology, automotive manufacturers can consider aspects of trustworthiness, and can also respond to the upcoming cybersecurity regulation.