This study investigates the interrelationship between interpersonal trust, team cohesion, and production efficiency within the Indian automobile manufacturing sector. Drawing upon Social Exchange Theory and Group Dynamics Theory, the research examines how trust-based interactions among employees and cohesive team structures influence the operational and production performance of automobile firms in India. The Indian automobile industry, being one of the largest in the world and a cornerstone of the national manufacturing economy, represents a highly relevant context for studying organizational behavior determinants of efficiency. A mixed-methods approach was adopted, combining structured questionnaire surveys administered to 420 employees and managers across six major Indian automobile companies—including Maruti Suzuki, Tata Motors, Mahindra & Mahindra, Hero MotoCorp, Bajaj Auto, and Hyundai India—with semi-structured interviews conducted with 30 production supervisors. Data were analyzed using Structural Equation Modeling (SEM) and thematic analysis. Findings reveal that interpersonal trust significantly and positively predicts both task cohesion (β = 0.68, p < 0.001) and social cohesion (β = 0.54, p < 0.001), which in turn exert strong positive effects on production efficiency. Team cohesion mediates the trust–efficiency relationship, explaining approximately 61% of the variance in production outcomes. The study concludes with theoretical contributions and practical recommendations for HR managers and production leaders in the Indian automobile industry.