My mother washed her Mitsubishi Colt every w/e in a car wash until she passed me the car after 5/6 years. Couldn't see out of the window there were so many little scratches. At night it was like a starburst. As to the paintwork....
To be fair, I used to hand wash all my cars, but after the third heart attack it simply isn't possible any more. I'd love to be able to take better care, but unless someone offers to do it for me it isn't gonna happen! That's why I only run it through the car wash every few weeks or so. I figure its better to keep it dirty than use the car wash every week and suffer the consequences... And I'd rather not wash it at all than trust the foreigners who do those handwashs on every street corner!