Yeah, what Jeff said about freezing yourself out of your car... I wash mine routinely when salt's on the roadways and there's any moisture. I keep cars for well over 100k miles too, so the body's important to me, so you should wash it routinely. It's important even if you trade them in routinely because you just don't want them rusting since that affects trade-in of course. All cars rust, it's just a fact of life. You can't always even tell where it's coming from. My doors are rusting from the inside out on my LeBaron because of a design flaw. My Thunderbird did the same thing... I had a hole rust behind my right front mudflap as well that I discovered this Summer when I took my flap off. This is with two paste waxes a year and routine cleaning with spray-hot wax in the winters... It just happens. I have the luxury of a brother who can weld well and knowing how to weld myself some, so we're putting patches on it and I'll primer it myself. It's all in areas nobody can see anyway.
If I didn't have that luxury i'd probably wash my car once a week if it's been steady snow/salt, snow/salt, snow/salt type weather.
That's just me though Rob, but I think frequently washing is good advice. Make sure you're getting low too, and using the high pressure wash on the undercarraige of your car so you're really getting that cleaned out. When it looks like you'll have a good spell then I think it's a good idea to wash it and do the hot wax at least.
Some people run theirs through automatics and that's good, but not as good as getting out and using the washer yourself and being thorough. That's my advice personally.
The snow coming off cars doesn't bother me a ton. My car tends to clear itself upon movement because of the ragtop. The snow doesn't stick to that, so I just basically clear the hood, lights, and trunklid... It's illegal in PA to drive with snow piled on your car though now so maybe I'm just not seeing it as much perhaps. I don't know the laws out there. Here you have to have yoru car cleared off pretty completely, and you have to have your lights on in snow, and so on. The bad stuff is when it's frozen **** and coming off vehicles... That can be much worse obviously.