Look into amsoil hd metal protector, I used about 3 cans when I first purchased my truck about 3 years ago. It dries to like a wax finish and the trucks been through 2 winters so far and it’s still hasn’t washed off. I’ve used fluid film in the past and this is way better.
I sprayed it myself took about half hour and used about 3 cans. I don’t see any downside or any problems to using it other then it being a bit tacky otherwise still looks new.
I did the amsoil hdmp on my truck when it was new and 2.5 years later it still looks brand new and I live in a rust belt. This also dries to a wax like finish and doesn’t wash off as easily as fluid film.