This thesis addresses the critical strength/ductility trade-off in aluminium alloys, particularly in the context of automotive applications. Traditional 5xxx series alloys offer good formability but lack sufficient strength, while 7xxx series alloys offer high strength but poor formability. To overcome these limitations, 5/7 crossover alloys have been developed that combine the best of both series. The resulting alloys achieve high elongation and significant hardenability, with yield strengths exceeding 400 MPa after industrially feasible thermo-mechanical treatments, making them ideal for advanced automotive and aerospace applications. This thesis includes a detailed study of the effects of heating and cooling rates, the simulation of industrial heat treatment processes and the unique properties of 5/7 crossover alloys. It also examines the acceleration of quality control measurements. The sustainability aspects of the aluminium industry are examined, highlighting the potential of the crossover alloying concept to accommodate higher recycled content and support a circular economy. Increased use of recycled materials in the production of these alloys introduces higher levels of impurities, particularly iron and silicon, which can adversely affect mechanical properties. Studies are therefore being undertaken to investigate the phase formation, nature and modifiability in the system of 5/7-crossover alloys. The goal is to develop advanced alloy design and processing techniques to counteract and mitigate their detrimental effects. The development of 5/7 crossover alloys represents a significant advance in aluminium metallurgy, providing a sustainable solution to the strength/ductility trade-off with unique possibilities in the area of rapid plastic and superplastic forming. This innovation paves the way for a shift from multi-material to single-material car bodies, enabling closed-loop recycling of vehicles in the future.