The tailgate, as the rearmost vehicle opening, plays a pivotal role in defining the rear aesthetic theme while ensuring structural durability and maximizing luggage space. Contemporary automotive design trends highlight an increasing demand for Y-to-Y tailgate-mounted tail lamp configurations, which deliver a bold and dynamic visual appeal. Enhanced by animated lighting features, these designs cater to the preferences of Gen Z customers, becoming a decisive factor in purchasing decisions. However, integrating these complex tail lamp structures introduces significant engineering challenges, including increased X-dimension volume, reduced design space, and intricate mounting schemes constrained by stamping limitations. These factors necessitate the development of innovative joinery strategies and structural definitions to maintain durability targets, including achieving 25,000–30,000 slam cycles without failure, while preserving luggage space. This paper explores a comprehensive approach