What's the point?
Whats the point to what ??? You know the thread was about washing a car and you know it makes a dirty car clean.
Do you mean why keep a car clean ??
You generally wash a car to enjoy it looking clean for weeks or days, it gives you a period of time when it looks nice.
If you wash it in this weather it will be absolutely filthy the next time you go out in it. So you spend a few hours washing it to see it nice for all of a couple of hours before you make it filthy again.
R888's in this weather? don't they have a min temp rating before they start falling apart?