The Research Department of the State Farm Insurance Companies, in response to the increasing demands of consumers, state legislators, and individual policyholders, has implemented several research programs to evaluate the production and performance quality of the aftermarket (AM) and original equipment (OEM) automotive replacement fenders. Collectively, the evaluations have been based on visual assessments of the corrosion resistance of coated fender components. Corrosion resistance was determined by analyzing the degree of red rust attack.In May, 1986, State Farm did contract out, to Battelle, a study of the corrosion resistance of 54 primed and/or topcoated replacement fenders (AM and OEM) after a 500-hr exposure to the ASTM B117-85 salt fog environment. The results of visual and microscopic (optical and SEM/EDX) examinations confirmed that the inherent corrosion resistance of topcoated AM replacement components was nearly equivalent to that of the OEM replacement components.A second program, initiated in May, 1987, by State Farm's Research Department, was designed to characterize the corrosion resistance of AM and OEM replacement fenders, as well as non-replacement OEM fenders (i.e., original fenders on the other side of the vehicle) that had been exposed to field environments (i.e., public roads) for a minimum of two years. Specifically, survey forms were sent to State Farm claim offices located throughout the United States. The first section, which contained claim information (i.e., claim office, inspection date, vehicle mileage,…) on a specific vehicle, was completed by State Farm. The second section consisted of a questionnaire that contained specific questions relevant to the present condition of the front fenders on the vehicle. These questions focused on the condition of the fenders, in particular, red and white rust, stone chipping, and paint coat blistering. (This study, however, only deals with the amount, frequency, and location of red rust.) Reinspectors from the State Farm claim offices are trained to inspect vehicles after they have been repaired. Thus, they were responsible for completing this section and forwarding all forms to State Farm's Corporate Headquarters.The information collected from a total of 450 completed survey forms in the field study was statistically analyzed. Comparisons and statistical summaries were made using data from both the lab study and the field study. Collectively, the results obtained from these analyses suggest that the corrosion performance of AM and OEM replacement fender components is nearly identical.