Teslas, like most cars, aren’t supposed to work without someone in the front seat. But as YouTuber AI Addict proves, all you need is a stuffed animal, or even a dang balloon, to trick the Full Self-Driving system into thinking there’s someone behind the wheel. (Full disclosure: these guys did these tests at the behest of Dan O’Dowd, a rich software developer who’s made it his life’s mission to debunk Elon Musk’s automated driving claims.)