Here we go again ORD! Dropped off at 4:30 AM and the return lane was very busy. The agent was checking cars one by one and I just left my car with the key on top of the cluster. After my flight I see no email and checked the app: car still checked out. Called up CS and the guy said that the car is already rented out! Closed out my contract and sent me the email. Baffles me that they do not have a warning or anything of that sort if a car is already loaned out and then someone else takes it for a spin.