Here in Ohio, it is the rust belt capital of the world, well maybe shared with Michigan. I undercoat my vehicles, especially ones that will see salt or other road de-icer. Ziebart undercoating works well. So does spraying with oil.
It is just a matter of managing your equipment.
Even our travel trailer, which never leaves the drive when it snows, gets some rust. I use a product named Os-Pho. It is phosphoric acid. It kills rust. I treat the rust and paint the spots. Problem solved.
The absolute worst thing that can happen is to have brake lines rust out. Everyone that does not live in the rust free areas of the country should make it a habit of having the brake lines inspected (on a vehicle that has them of course).