Earlier in life, I shared an apartment with a guy named Jack. Jack had a Ford Fiesta. I drove in from work one Saturday and as I turned into the parking lot, I noticed the hood up on the Fiesta and Jack standing in front of it. Looked like an oil change in progress. I parked and was walking across the lot and I noticed the tip of what looked like a growing oil slick running out from under the back of the car. "Hey Jack, what's this?" Turns out he'd forgotten to put the drain plug back in and whatever little bit of oil a Fiesta used, went in the top and out the bottom and was slowly tricking down the slope of the parking lot.