You say that, but in reality you wouldn't.
You'd be too busy driving it and enjoying it to spend hours a day cleaning it every day.
I find the notion that only expensive cars should be cleaned like this very strange. Very similar to how I find the notion that nice cars must be washed religiously or your not properly looking after your car very weird. Cars are built to be enjoyed and drive, not ornaments.
Fair play to those that do, but that doesn't make you any less for not doing it. Eyedots used dirty F40 is brilliant to see - an F40 being used properly and not sat in a garage kept pristine clean and never driven for fear of making it dirty again.