I got Model X 90D in March. About two weeks later, I drove the X to Vegas with my wife and two little girls. After we got on the freeway, I started to use autopilot. The weather condition was great. I set the autopilot at the speed of 80 mph with 5 cars distance. I was very cautious with this Autopilot technology, especially my whole family was in the car, so I kept my eyes on it. It was very amazing when the car drove itself on the freeway at the very beginning, but not too long, I saw the car in front of me was slowing down, but the X continued to accelerate to 80 mph, even though it detected the front car! In the instrument panel, the front car became red and warning beeping sound alarmed, but no sign of auto braking. I immediately brake the car, and fortunately enough to avoid crashing into the front car. It all happened within seconds. My wife called Tesla customer service to report this incident a few minutes later. The service rep on the phone seemed not too surprised and told me he had a similar situation while driving his own S. We paid $2500 to add autopilot feature, but it's Beta version. When you use beta software in your computer, your computer might crash, not a big deal, you can always restart the computer and uninstall the beta software. But, when the Autopilot is beta, and if it crashes, there is no restart button... Is it Tesla too soon to add autopilot? I think it is.