In the last decades, sustainability has become a critical issue for the vehicle industry. Today automotive manufacturers are subjected to several government regulations aimed at making the industry more environmentally sustainable. In this context, many research and industrial activities are focused on the eco-design field by developing innovative materials, novel manufacturing technologies, and new methodology; the main objective is to combine the best design performance with increased environmental responsibility. In this paper, a holistic design and sustainability analysis method based on a multi-criteria approach is presented to support the designer in the early conceptual phase finding the best trade-off in terms of performance and sustainability. The new methodology generates a single-score index (SSI) based on product design/sustainability metrics; data normalization, weighting, and aggregation processes are also included in the evaluation method. This method is integrated into an eco-design framework developed through HyperWorks and MATLAB software tools. A case study, based on a reference geometry, a load case, and a list of materials and processes chosen by the designer, is described to show the potential of the proposed methodology. Finally, a critical review and concluding remarks are described following the SSI results; suggestions for further improvements are made.