You know, I was thinking about for a bit, and it didn't seem like all that bad of an idea. Just like what truck people do, I was thinking of spraying the underbody with bed liner. Sounds pointless, but here me out. These cars are famous for rusting out down there and why not prevent it? I mean you can tell future buyers they won't have to worry about rust anytime later. I might do it if I have time.