Cars should just give you access to the cameras that are already there. Why get a rear facing camera when your car is already legally required to have one?
I've wondered this too. Even if it's only the rear camera all cars should have a few seconds of rolling buffer that they save whenever an accident is detected. At the very least if the airbags blow it should trigger the save. You only need enough storage for maybe 10-15 seconds of footage.
I would also like the ability to turn on the rear camera when moving forward, for those times when the rear view mirror is blocked, especially on vehicles where the backup camera is integrated into the rear view mirror.
