I gave mine a good under-side pressure washing, thorough top side washing, and a solid coat of Collinite 845 yesterday (61*F!), to prevent the EVIL sodium/calcium chloride from doing it's destruction!
The problem is now, the illustrious PennDot (and the local DOTs) has/have dumped so many TONS of that shit onto the roads during the last few flakes which fell, that there is a thick coating of salt dust on them, so I have to study the hourly weather in order to 'dodge the rain', and keep that effing salt soup crap off the car, until it rains hard enough to wash it all away! GRRR!