Undercarriage car wash - GIF

[ductape]

Salt on roads will melt ice and snow until about about 15F/-9C, depending on ground temperature. Below that point, road crews start using calcium chloride, which works very well but is a good bit more corrosive to all kinds of steel than salt, even stainless. Also not especially good for aluminum. It's a good idea for anyone living in those areas to wash it off whenever they get a chance.