I thought about the touchless car wash, but a number of sources said the chemicals and high pressure spray strips the wax and sealant off the paint finish, leaving the paint exposed. My current plan is hand wash the car when temps are 30'F or above (which will become very rare in the next few months), plan B is to use a DIY car wash stall with my own brush and soap, and plan C is to use an automated car wash. I actually have enough wax and paint sealant on the car that most of the salt comes off with the hose and just needs a little bit of brushing to clean the car. So far, I have been able to hand wash my car this winter. Last month we got over 30" of snow and temps way below average. I was able to time the hand washes according to the weather and avoid the automated or DIY wash bays.
A trick that was passed to me from a rally team is to spray the bottom of the car with WD40 as it will make it easier to clean the salt off.
This past weekend I made some additional underbody protection panels out of UHMW;

After a few weeks of driving in the snow, I noticed ice buildup on the rear half of the skirts. Today I added some protection under the skirts and extended the front mud flaps. Hopefully this will help protect the car better. by
Bryan Redeker BRGT350, on Flickr
The plastic sheets are located under the rear doors and mounted to the side skirts. They have a removable door for the jackstand/rear jacking point and run from the factory floor pan plastic shield to the rear wheel well and about 10" to the inside of the floor pan. They also protect the skirts, rear doors, and rear quarter panel from debris coming from the front tires. I also lowered the front mud flaps to cut down on the angle debris can exit the front tires.