I have a 2018 Tesla Model X, HW3 with the latest firmware at the time of this writing (2019.31.12.2) and a high-speed USB drive to capture dashcam footage - worked fine until now. I was unfortunately rear-ended by another driver - luckily fairly minor damage. About a minute after the accident I pressed the Dashcam icon to save the most recent footage thinking I was covered. Only to find out when I got home that the actual accident footage wasn't there. It saved everything before, and everything afterward, but not the actual accident! Likely there's a software bug that corrupted the file during save in some way. Super disappointed that when I needed it most, it failed. If you really want a reliable dashcam, better get a third party one.