At a coin car wash after the rainy season

Overview

The setting is a self-service car wash in Shinagawa, Tokyo, where people line up to wait their turn. Using spray bottles filled with water and detergent, they take their time polishing their beloved cars. A woman who bought a car for work but has since become so fascinated by it that weekend drives have become indispensable. A couple who wash their car instead of going on a date. A man in his 70s who is considering returning his driver's license. Each with their own circumstances, they silently wash their cars. At the end of July, after the rainy season ended, what do they want to wash away along with the dirt on their cars?