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NVH refinement of a vehicle with light weight structure[1] focusing on fuel efficiency is a challenging task. Resonance between the air volume of the cabin and revolving engine excitation generates booming. This booming noise affects the annoyance of sound quality in the cabin. Engine torque variation, penetration of air intake and exhaust system, and tire unbalance caused by engine auxiliary resonance are the most influential sources for high speed booming. This paper describes the booming noise level reduction between 100-200 Hz during high RPM driving conditions in one of the passenger cars. Detailed CAE iterations and testing has been done to identify the root cause of the booming noise. By considering the cost vs NVH performance trade off, the optimized NVH countermeasure has been chosen and validated. Modal analysis, operational deflection shapes, Input point inertance and Noise transfer function techniques have been used for root-cause analysis and counter measure proposal.