hydrophilic paint protection is simply a paint sealant. The final application in detailing works. I would only surmise that this procedure is safe as its miscible with water. As for the cost, I wouldnt really know how much they would charge per sedan. Ask Big Bert of thier paint sealant, Last time I had it with my car, I saw ther material, its Eagle One Floroupolymer Paint Sealant, very effective and lasted very long.