The paper seeks to determine the manufacturing productivity parameters used in the automotive industry in South Africa. The downtimes, rejects, rework, takt times and quality of the products in both the night and day shift were found to be effective. The parameters caused bottlenecks which increased the takt times through the manufacturing 4Ms, namely materials, methods, machines and manpower. Durations of each downtime for each M were recorded and the root cause established using the 5WHY interrogation.  The theory of Constrains and Lean Manufacturing tools were applied to subordinate and minimize the cause of problems through continuous improvement (CI). The machine downtimes, rework, reject, methods failures and any inconsistencies-initiated CI in the automotive industry. A layered process audit was done by line managers to get the defect trend using root cause analysis before standardization. The safety of staff and machines was audited to establish and eradicate the near miss and sustain the lock Out, Tag out (LOTO).