Tesla's latest firmware update comes with more than just bug fixes -- there are a pair of fun surprises just in time for the holidays hidden in there as well.
Model X owners can activate a secret light show that transforms the SUV into a four-wheeled disco ball. To activate it, you simply press the Tesla icon at the top of the screen for 5 seconds and then enter "Holiday" in the passcode screen that pops up. Once you exit the vehicle and lock the doors, the X will set off its exterior lights while playing music.
Both Model X and Model S owners can try the other hidden feature. Just enter "Mars" into the navigation's destination zip code field and it will replace your local map with one from the surface of the Red Planet. As you drive, the surface map will pan accordingly but, alas, you'll never actually get any closer to Mars that way. You'd need a spaceship for that.