Daily driver gets washed whenever it rains. GN has only been washed twice in the 9 years I have owned it. Doesn't see bad weather so I just use Meguires Final Inspection trigger wash on it.
if you keep your car waxed, (i use Zymol), you can often avoid washing it and get away with misting and wiping it down with Meguires Quick Detailer spray. Unless the car is heavily soiled this works fine for me as long as the car is waxed
I just use a California duster on the GN when its dusty. Daily driver is washed about once every 2 weeks unless there's rain in the forcast, then I just leave it till it isn't going to rain for at least 4 or more days.