The industry of automotive components is highly competitive. Polymer injection, used to over-mould conduits, is used to produce the necessary connections between the end of the Bowden cables and the car parts where they need to be assembled. Depending on the vehicle or the use, there will be a different connection of the conduit. The industry continuously looks for greener and more sustainable solutions. This study presents a strategy to save energy in polymer over-injection moulding. The developed concept consists of replacing the previous moulding system by a custom automatic one, using two more compact injection machines and automation, allowing for increased productivity and sustainability, all while retaining operators’ jobs. An application of the novel methodology is presented, reporting an energy consumption reduction of about 80% and an increase of 12% in production rate. With this work, the benefits of automation for overcoming sustainability and productivity problems are highlighted. Furthermore, the developed strategy may be applied to other production processes, regarding the injection of small parts in large quantities for a variety of materials.