I just got a new truck well new to me 99 f250 ext cab 8ft bed 7.3 it's a cali truck so no rust at all and I want to keep it that way. I'm looking for options I was thinking of using old motor oil and diesel and mixing them in a sprayer and coating the truck every few months. I was thinking about undercoating it but everything I've been seeing that por15 and other brands just trap moisture once they start to flake and the rust comes back through or it will rust. I was looking for some suggestions since I live in PA and penndot loves to use an over abundance of salt.