Rust in the front fenders seems to be a common circumstance with trucks in this year range. I realize this subject may have been beaten to death, but why are these fenders prone to rust in the first place? I searched the forum and couldn't find an answer. Is it a design flaw? and if so, when replacing the fenders, what can be done to prevent water gathering and rust happening in the new fenders? Other than the obvious answers such as undercoating and a good paint job.