I wash mine weekly. I have access to a wash stall inside the auto hobby shop. This stall is heated so I'm not exposed to the outside when washing my car.

One weekend, we took BP's car there and gave it a good washing so he knows just how good I have it where I work

Biggest thing is to keep the salt from building up and keeping it off the car as much as you are able.... Anyway that's my plan for the winter months, especially while its real cold outside....