I think his point was that there wasn't any oil to begin with. We're talking about washing the outside of a vehicle, not changing the oil. We're washing off dirt that accumulates from being in the environment.And where would the oil go once on the asphalt? And where did the floor drain go?
I'm totally with Berner73. As environmentally friendly as I like to be, a little dust in the water is pretty insignificant compared to the alternatives. Kinda reminds me of all the people that think Hybrids are good for the environment just because they get good gas mileage...ignoring the byproducts of their construction and disposal.