Recent global energy markets and supply chain disruptions have reiterated the necessity to improve the efficiency of transportation systems. In the U.S., one of the biggest automotive and energy markets, transportation accounted for more than a 1/4th of all energy consumption and resulted in nearly 1/3rd of all CO2 emissions. Although many approaches have been investigated to improve the fuel efficiency of vehicles, light-weighting has proven to be particularly effective as it allows automotive original equipment manufacturers (OEMs) to improve fuel efficiency, incorporate value-adding features without a weight penalty, and extract better performance. Historically, there have been several successful attempts focused on body-in-white (BiW) light-weighting as it accounts for more than 35% of the total vehicle weight. However, closure systems, which account for almost 50% of the total structural mass of the vehicle, are often overlooked. This is because closure systems need to meet a diverse range of design requirements such as crashworthiness during side impacts, stiffness, strength, corrosion resistance, durability, fit and finish, NVH and weather sealing. Since many of these design requirements are same as those of the larger BiW, light-weighting approaches using fiber reinforced (FRP) composites developed for closures can be translated to light-weighting other structural system of the vehicle as well. Thus, the U.S. Department of Energy’s (DOE) Vehicle Technologies Office has initiated a multi-year research and development program to enable cost-effective light-weighting of the closure system, in this case the driver side door, of a commercial SUV. The designs developed as part of this initiative would enable weight reduction of 42.5% compared to the baseline steel door system, with a maximum allowable cost increase of $5 for every pound of weight reduced. Furthermore, the conceived designs were to be compatible with large-scale composite manufacturing processes to enable production of at least 20,000 vehicles annually. With the growing focus on use of sustainable materials and enabling recyclability, the designs were to enable 100% recyclability for the structural components. This addresses the increasingly stringent regulations such as the 95% recyclability required as per European standards. To address these objectives a wholistic systems design and optimization approach was adopted to ensure development of feasible carbon fiber reinforced plastic (CFRP) composite designs. In addition to superior specific mechanical properties, composites also enable significant parts consolidation. Thus, many smaller stamped components and reinforcing brackets were consolidated into two distinct high-performance carbon fiber reinforced thermoplastic (CFR-TP) composite parts suitable for fast and scaled production using thermoforming. The systems approach followed in design conceptualization, allowed for nearly 40% parts consolidation, which in turn reduced the tooling and assembly costs significantly. The systems approach employed, the design studies conducted and resulting assessment and down-selection of feasible designs are being presented in subsequent sections.