A North American Automotive OEM asked Sound Answers to investigate the mechanisms that affect the sound quality of a door closure event. A target vehicle, with good door closure SQ, was measured along with a Customer vehicle. Each vehicle was instrumented with seal pressure measuring system, accelerometers to extract Operating Deflection Shapes, strain sensors to estimate forces at latch/striker during door closure event at a controlled speed. Near-field Acoustic Holography (NAH) measurements were also conducted to visualize the noise radiated from the door surface as a function of time and frequency. The data collected from each vehicle were then analyzed and compared to those from the other vehicle to draw conclusions regarding the physical differences and formulate hypotheses of dominant controlling mechanisms.