My 07 Ram is showing rust at the top of the wheel well on both sides of the bed. The metal is not rusted through, paint is bubbling with rust/pitting of the metal. All metal feels to be solid at this point. I am p-lanning on installing fender flares and splash guards to cover and protect the affected areas. What is the best materials to use to prevent rust on the exterior surface and to protect/prevent additional rust in the areas on the inside of the wheel well?