For me, it is about how often I would have to wash it to maintain appearance. I have a really pretty motorcycle, an Ultra Classic, H-D, truthfully, it is grimy as hell. If I cleaned and polished it every time it really needed it, I either wouldn't have time to ride or wouldn't have time to work. I do preventative maintenance and keep things from corroding, but it only gets a proper cleaning every other year. I run at least 6-800 miles a week in my truck, it gets washed when it rains except for winter months, in the winter I rinse salt from the body and undercarriage every couple of weeks.
