winter body care

Gentlemen I own  a sweet 2000  cadillac seville 77,000m . I live in Buffalo , NY and the roads are infested with salt. Unfortunately I have to drive the caddy in the winter; my question is how can I minimize the damage of the body from the salt? I try only to drive it when the roads are dry. I also avoid driving it when the conditions are rough weather wise. Does  salt do damage to the body while the outside temp is cold or when the temp warms up. How many times should I wash the caddy during the winter. I love this car so much  that Ill wash it every day if it is suggested. I garage every night . Any suggestions on how to keep the rust off and I will comply thoroughly. 

Find carwash that offers under body cleaning, it's like a power washer that sprays underside of car, then go there once atleast once a week. If you can every time the roads clear of snow and ice. Inspect and attend to paint chips as soon as you see them...rock salt and/or cinders can cause them.