I had my first test drive today, and of course was duly impressed. I had not realized that the Model S already had the ability to warn you via a vibration in the steering wheel if you were deviating from your lane without signalling. (I knew that was coming--just didn't know it was implemented already.) But the big news that I wanted to share is that according to the rep who showed me the car, in two weeks Tesla will be delivering a software update to the cars with the autopilot sensors that will allow for the implementation of Adaptive Cruise Control. He seemed quite certain of this. I hope he's right!