The paper discusses the stress analysis of a plastic model passenger car frame using road forces recorded on an actual vehicle. This test vehicle was instrumented to record suspension member forces and then driven over various durability routes. These suspension forces were then analyzed for instantaneous peaks, which were input statically to the plastic model chassis. The model frame was stresscoated and strain gaged to determine stress levels for the various road profiles and vehicle maneuvers considered. The procedure for the actual construction of the plastic model and its environmental test fixture is explained in detail.The paper illustrates the ability to use plastic models as a design tool to provide feedback to the engineer. The information obtained in the test was not only useful in locating potential structural problems, but it also helped in evaluating manufacturing and ride development changes for design feasibility and cost efficiency.