Presently, plastics are widely used for car interior trims; however, with the growing importance of reducing vehicle weight, plastics application to body and chassis parts is ever on the increase. This tendency results from both the development of new plastics which are applicable to structural components, and the new manufacturing processes which have shortened cycle times. We can find many practical uses for plastics in automobile body parts. Plastic bumpers, including RIM fascia, are not only lighter, they are also less susceptible to damage. This is because they soften the car front and rear ends. Glass fiber reinforced RIM has been applied to exterior panels. Experiments with urethane injections have been conducted in an attempt to improve member strength and stiffness. In addition, composite materials reinforced with carbon or glass fiber have been used, on a trial basis, for such chassis parts as leaf springs, wheels, propeller shafts and engine mounting members. This paper deals with the weight reduction, the functional improvements, and the integration and simplification of components which can be realized through the application of plastic technology to automotive components.