Thanks for the comment!

Which leads me to my actual point — I wash my car to get that road salt off of it. And not just off the parts that you can see; the important parts are the ones you can’t — underneath the car. The ones that rust if left alone. Even if you do hand wash your car in winter, you’re still going to have a hard time getting the undercarriage clean unless you use a pressure washer. And just spraying the underside of the car could make things worse by dissolving the salts and leaving a salty solution sitting there to rust everything it touches. I’ve done the DIY car wash (where you put in quarters to use someone else’s pressure washing setup) in winter before, but it always costs me the same as an automatic car wash.

Again, if you live in a warm climate or don’t plan to keep your car very long, this doesn’t apply to you. But otherwise, car washes are not simply cosmetic, but an important part of preventive maintenance, just like oil changes.