Engineering plastics have been applied to automobile components to reduce the weight of an automobile and in essence, improve fuel efficiency. In this study, the application of polycarbonate/acrylonitrile-butadiene-styrene copolymer (PC/ABS) based composite material to the car audio chassis was investigated with respect to the key properties of a car audio chassis mainly through vibration analyses, injection molding analyses and electromagnetic interference shielding effectiveness (EMI SE) tests. A PC/ABS based composite material was designed for replacing carbon steel of current car audio chassis. Before mocking up a prototype of a car audio chassis, two key factors, i.e. injection molding analyses and vibration analyses, were investigated numerically. Next, an actual injection molding of a car audio chassis based on the injection molding analysis results was carried out for various temperature conditions and two types of catapults. The optimum temperature condition and catapult type were determined by observing the distributions of composite fillers of the injection molding chassis microscopically. In addition, base excitation vibration tests were executed to obtain the vibration characteristics of the car audio chassis, Finally, EMI SE of the newly designed car audio chassis was measured to determine whether the injection molding chassis satisfied the EMI SE regulation.