The facilities used by domestic automotive manufacturers to provide accelerated corrosion aging of complete vehicles are described in general. The types of vehicles tested, general test methodology, and techniques used to determine test-to-field correlation are discussed. The different procedures used throughout the industry produce different results on various vehicle coatings, components, and systems. The key to successful interpretation of test results is a thorough understanding of the corrosion mechanisms involved and the effects of test limitations on these mechanisms.