People are doing all kinds of silly things while playing with the self-driving mode of the Tesla Model S. Apparently, some Tesla owners have even tested it while being in the backseat. As you can imagine, these type of activities could have serious consequences, so Tesla limited the capabilities of their self-driving mode. But even so, you can still have some fun. For instance, you can make your Grandma freak out completely, as long as she has a strong heart. This is hilarious!