Hi everybody... I'm finding conflicting information about this. Some say that when the car doors are locked, two flaps close over the tank opening that will only fit a gas tank nozzle. I'm also finding gas cap locks for 2015 Mustangs sold on various websites, implying that they don't come stock with their own lock.

The reason I ask is that for the past two afternoons, I've come back to my car to find the gas tank door sprung open, after parking in the same location in the morning and locking the car.

I tested it just now, locked the car with the remote and was able to not only open the spring loaded door, but also open the flaps with my thumb, and push the end of a wrench into the tube that leads to the gas tank.

This concerns me because I have reason to believe a particular person may have tampered with my gas after I parked it. It's running just a little rougher than usual. Or, maybe it's just 100-degree heat causing vapors to expand and pop the door open (??) The dealer service department is closed right now, so thought I'd see if anyone here has more information. Thank you very much!