Four hundred miles with Tesla's autopilot forced me to trust the machine

As we pulled back into the showroom (or whatever Texas' insane dealership protection laws demand Tesla call the places it's not allowed to sell or service vehicles), I told the rep that I was driving to Austin soon; Autopilot would be just the thing for the long stretches of empty road out on I-10 and TX-71. Without missing a beat, she offered me a loaner Model S. Ars has officially driven a Model S with autopilot before, but only under controlled circumstances. The Austin trip would let me take the car out for nearly four hundred miles of driving in a big mix of traffic scenarios. Plus, I'd get to log more cockpit time in a Tesla. Of course I said yes.