We get salted roads here but not like you guys up north. I do wash under my cars often and all the vehicles I have purchased including my old ones get jacked up way high and a power washer is taken to the under side of them. All crud is removed and prepped for undercoating. Then they get rubberized undercoating or spray painted black. I like it clean and fresh under my cars.. buddies think it is nuts to spend hours under a car doing that. But a lot of off road in mud. to get to some of my fishing and hunting spots. Stuff cleans up easy and it is protected a bit better.