OK. I'm kind of loathe to do it in the driveway because the greasy, oily crud waste ends up in the groundwater. At least with the carwash places they're supposed to process the waste, and even if they don't. at least it ends up at city wastewater treatment, for what that's worth. Here where I live we're on septic and well water and if I do it here, we and all the other critters that live around here end up drinking greasy wastewater next week.