At an event last night, Elon Musk finally gave us the D: A dual-motor, all-wheel-drive version of the Tesla Model S. On the top-of-the-line P85D, that second motor brings the max speed up to 155 mph and 0-60 mph down to 3.2 seconds -- firmly in supercar territory. Musk also announced a new 'autopilot' system for all new Tesla cars, which can automatically change lanes when you push the turn signal stalk, automatically reduce your cruise control speed when its forward-facing camera spots a new speed limit sign, and other self-driving functions.