Vehicle rattle noise, generated when parts impact each other due to road, wind or powertrain induced vibration excitation, has become one of the major customer concerns in recent years. Traditional find and fix methods for rattle problems rely on a subjective assessment in identifying and locating the rattle before corrective action is taken. This paper presents a simple technique to quantitatively determine the location and strength of rattle using a microphone and an accelerometer. A CAE tools had also been introduced to identify potential rattle hot spots early in the design process before prototype vehicle have been built. The correlation between the experimental technique and CAE prediction for identifying rattle sources in a prototype vehicle is also presented.