An article in Crain's Chicago Business indicates that they may partner with Walgreens for parking spaces, as they did with Lowe's.

"The pilot program in Chicago let customers rent a car via the Hertz site or app. After completing the transaction, customers received a numerical code to type into a keypad from outside the driver-side window or front windshield. The keypad, inside the car, is sensitive enough to pick up the strokes through the glass. The code opens the door; the keys are waiting inside."