on 26/10/2019, Andy Burns supposed :
Some dashcams also record the rear as well

My dashcam includes a lower res. separate rear camera. Its a rather
like a slightly smaller than a 35mm film container.

In addition to which, I have a rear facing reversing camera, which
displays on the big ICE screen in the centre dash when reverse is
selected, plus reverse sensors. Rear window is high and a narrow slit,
obstructed by rear headrests - the only useful mirrors are the door
mirrors, so I felt the reversing camera was essential for safety.