"How can lean manufacturing principles be effectively implemented in a multinational automotive manufacturing company to optimize operational efficiency and reduce waste across its global supply chain network? Discuss the key strategies and challenges associated with integrating lean practices into diverse cultural and operational environments, ensuring consistent quality standards and timely delivery while minimizing costs and maximizing customer satisfaction. Additionally, explore the role of advanced technologies such as artificial intelligence, IoT, and big data analytics in enhancing process visibility, predictive maintenance, and inventory management within the lean framework. Evaluate the potential impact of implementing lean methodologies on key performance indicators such as cycle time reduction, inventory turnover, defect rate, and overall profitability, considering both short$-$term gains and long$-$term sustainability goals."