Many questions have been raised about the need for and effectiveness of aftermarket rust protection, but no clear and precise answers have originated from applicators or manufacturers of the products. This paper will address three major issues related to aftermarket rust protection: where to put the product, what product requirements are necessary, and how to apply the product. Product performance will be established by corrosion testing on uniprime, G90 galvanized, and production steel test panels, representative of the materials used by the auto industry. Application requirements will be established by comparing the more conventional holes-drilled method to the newer fogging procedures, showing the deficiencies of these fogging procedures. Finally, this paper will establish that aftermarket rust protection benefits the consumer provided the materials used are effective corrosion preventives, the application procedures assure total and uniform coverage, and the amount of material used related to the performance criteria of the product.