Fluid Film is widely considered one of the best undercoating options (especially for long-term rust prevention in harsh winter/salt environments) for several specific reasons that set it apart from traditional rubberized/underseal coatings or basic oil sprays. Here's what makes it stand out: Why Fluid Film Is Often Rated #1 Lanolin-Based (Wool Wax) Chemistry Made from lanolin (sheep wool grease), it never dries or cracks. It stays soft and “creeps” into seams, welds, and microscopic crevices for