Advantages of leaving the car dirty:
The external dirt crust acts as a cover and protects the bodywork and paintwork from more dirt
You save water and cleaning material, or at least the amount you would pay to have it washed
If you don’t pay to wash, the demand decreases and the car washes must reduce the price they charge
Does not discharge detergent or soap into the environment, therefore environmentally friendly
Prevents boyfriends and looser people from leaning against your car and using it as a seat or support
It avoids parking lot attendants and traffic light beggars, who will look for other nicer, washed and smelling cars to hustle.
It (hopefully!) keeps out thieves and hijackers, who will look for other, cleaner cars to steal
Promoting a competition of which car has been the dirtiest or the longest unwashed can be fun
A car that has never been washed, or washed very little, keeps the new car smell for up to 20,000 km
Even the other (better and cleaner) cars avoid hitting dirty and battered cars, for fear they won’t even have insurance to cover the cost of repairs, and will be left on their bill.
Whenever we wash the car, it rains, so not washing can be an attempt to chase away the rainy weather
I’m sure there are more, but these would be enough.
