This last update changed the default settings for how my X behaves in a way that is outright dangerous, and it was never mentioned in the release notes. From my email to Tesla support: "We do not use autopilot at all - our roads are steep, narrow and curvy, and often do not even have centre lines so there is no point. The new release has introduced a 'feature' that attempts to take control of the wheel if the car thinks you are leaving your lane. In our case this results in the car swerving towards the side of the road or into the oncoming lane and only very quick reactions and overpowering the wheel (and so far, luck) keeps the car on the road. We've disabled the 'feature' but it enables itself every time we drive. At the first place it routinely attempts to take us off the road the bank falls away several hundred meters. As you can imagine this is quite frightening. Please let us know how to permanently disable this feature." The answer, in short, is that there is no way to permanently disable the new "Emergency Lane Departure Avoidance" feature. As I said to support it's like having an invisible crazy uncle (Elon?) wake up and grab the wheel at random intervals. On our roads that's really unsafe. The feature must be disabled EVERY TIME you start the car, AFTER you shift into drive. Otherwise it will reset and surprise you. It appears to attempt to wrest control on narrow roads with blind turns and steep banks, and will attempt to turn you either towards the drop-off or into the oncoming traffic lane. With quick reflexes and upper body power you are able to hold the road. It's only momentary, but unexpected and quite frightening. I'm not willing to just let it go and see if it actually takes me over the edge. I can testify that it's completely changed the experience of driving the Tesla. It used to be both relaxing and exhilarating due to the speed and power. Now it's still exhilarating, but mainly because I'm never quite sure what it's going to do. It's also completely changed the feeling about getting an update. We feel we have to re-test the car every time to catch any other surreptitious 'improvements' that could prove dangerous in our conditions. Perhaps the training data is not deep on left-hand roads? What we have here is a statistical trolley problem. I'm assuming that Tesla engineers decided that the lives to be saved from catching incompetent or sleepy drivers in highway driving outweigh the odd competent driver that was not asleep but was unprepared for the car to steer them off the road or into oncoming traffic on a blind turn. Tesla is running an experiment using it's drivers as guinea pigs in order to gather the data. My view is that sacrificing even a few otherwise competent and alert drivers in order to save even a large group whose actions or inactions might otherwise injure them is the wrong choice in principle - but I can see the argument. I also object in a 737-Max kind of way to a manufacturer changing the way a piece of equipment operates in a potentially fatality causing way without making sure the operator is well aware of the change. I don't mind software updates adding a game or prettying up the user interface, but if they are going to change the way the car physically performs I want to know BEFORE finding out in practice. This major change in the way the car behaves is not even listed in this update which was supposedly only about updating the training data for wipers! If this results in a death or injury Tesla can expect to be held liable with prejudice. Luckily for us we've picked it up in several non-fatal episodes. Finally, I want to be able to trust my vehicles (I am someone that built and flies his own airplane). I rely upon them consistently performing in a certain way, and really don't want someone else able to arbitrarily change that at any time without my knowledge or permission. That might eventually mean 'jailbreaking' the Tesla to disable autosteer, or selling it to get something with an equivalent electric drive train but without software that is trying to drive for me. The Tesla has changed from being the safest and most relaxing car we have to drive to the one that requires the most vigilance and paranoia. Unfortunate.