If its pissing it down...leave it?
The paint ain't gonna die if if its not washed and waxed 3 times a day.
Theres nothing like a nice shiny car but why do it in the rain. Let the rain wash all the dust off for you. Onces stopped, come out and clean the water marks off.
It's not as easy as that. When its raining the crap and dirt from the roads when driving starts to build up, splashes etc from other cars, vans, lorries etc builds up too. Before you know it, its pretty dirty. In this weather lately, I might get an hour or two restbite but I'm not always sitting waiting for the rain to go off so I can run out and clean the car. The rain doesnt wash it off in the slightest.
Not sure about anyone else, but I hate my car with dirt on it. I like it looking clean and shiney both on the outside and in.