He was using the power of the heavy rain to clean off his car and using the scrubbing brush to get off the hard parts, like stuck bugs. He was saving water the smart way, making use of what was naturally there. He let the hard rain do 95% of the work and was saving money because he has to pay for his water usage but rain is free. As for getting wet, you get wet washing a car, what is the difference if it comes from the sky or a hose?
It made me think of the other ways people take advantage of rainfall. Farmers often have cisterns or other ways to store rainwater to be used to water the crops, given to the animals or used to clean things. I remember always having rain barrels where we could collect rainwater and then would use it to water the garden on hot dry days. It made sense then and now. Water conservation needs to take place now more then ever and yet most people don’t think about it that much. Water from a tap makes it convenient and it is hard to think that it might not be so easily available someday.