What is the best way to take care of a car from “salt” spray, etc. during the winter? Do you go and give them under carriage washes?

Please, no replies of move south or garage it for the winter.

 

pressure sprayer and a jack.

 

I don't remember where I saw it but, I have seen a device made from PVC pipe that could be rolled under a car to wash the undercarridge. It had two wheels and a horizontal run of pipe with small holes drilled in it. It had an adapter to fit a garden hose for the water supply. Looked like it would work to me.