The thing about their plan though, if you read the post entirely, is that this new car with the new sensor comes with almost all features disabled. The reality

The thing about their plan though, if you read the post entirely, is that this new car with the new sensor comes with almost all features disabled. The reality is, with machine learning, you need a lot of data, and yes, you can send a few of your own cars with employees inside like Google, but that's slow. Instead, Tesla is using their existing brand and user base to collect orders of magnitude more data, and this way, they will be able to validate their models much faster. Again, the thing with data and algorithms is that you can test and retest them. When you have all the data, you can see the info at time X, and also have access to the data at time X+1, so you can check if your algorithm made the right choice. Furthermore, you can actually take tricky situations and replay them thousands of time while tweaking your algorithm to do better. So yes, while getting it right is very important, I believe their approach of collecting as much data as possible is the best way of getting there