I don’t know why cars don’t come with built in dash cams yet. Seems like there is huge demand for it.
I have a Subaru with the EyeSight system for lane detection, adaptive cruise control, etc. It’s annoying that the cameras are RIGHT THERE and always on, and they even store a 22-second history that can be accessed by police or insurance in case of a crash, but I, as the vehicle owner with a vested interest in access to the feed, have no way of tapping into it and storing it for myself.
My info came from the forum posts I found while explicitly looking for how to use the cameras as a dashcam a while ago. Some of them linked to the spots in the user manual that mention the 22-second loop, but the manual doesn’t have more info on how the access works. All I really know for sure is “we haven’t figure out how to get to it ourselves” and the rest is what I picked up from those threads.