Steel and aluminum material production are hotspots for the automobile industry. Automakers must urgently implement low-carbon procurement, thereby incentivizing raw-material suppliers to accelerate decarbonization. With support from the Energy Foundation, IPE launched the second phase of the research in September 2025, aiming to further examine how green supply chain management and information disclosure can promote coordinated carbon reduction across the automobile industry, guiding automakers to drive the low-carbon transition of the steel and aluminum industries.