Purpose The purpose of this paper is to profile the way in which Volvo Cars Gent (VCG) Belgium and its suppliers succeed in managing their interdependencies on HRM issues through a shared HRM collaborative, called the Suppliers Team Volvo Cars HRM forum (STVC-HRM). Design/methodology/approach - A case study approach is used to develop understanding of the critical factors that contribute to the forum's success. Findings - It was found that the critical success factors concern the way STVC-HRM members enacted trust common ground, leadership, shared responsibility, and representative-constituency dynamics. Research limitations/implications - To understand the Toyota system of successful collaboration and learning with suppliers, it is necessary to look into the actual assembler-supplier relationships and practices developed. Practical implications - Building lasting manufacturer-supplier relationships is considered to be one of the elements that contribute to Toyota's competitive advantage in supply chain management. However, other organisations struggle to improve manufacturer-supplier relationships despite applying seemingly similar principles. The paper helps in recognising and managing the main collaboration issues at hand. Originality/value - The work suggests how to build and maintain deep mutually beneficial manufacturer-supplier relationships through the VCG-suppliers case. Other organisations that want to develop those much-needed relationships may learn from the successful VCG-suppliers way of doing things.