As above, where can I find an easily accessible location?

Do you mean a stand alone rear camera? Most usually are powered from the main front camera.

Stand alone rear facing camera.

I would suggest a very simple option would be a normal but small dashcam, powered from the 12V socket on the LH side. Depends how much of a stickler for hidden cables you are. The socket is ignition only. If already blown, it’s fuse is behind the glovebox. All dashcams come with a cig-lighter plug lead as well as hard wire kits.

Edited 23 June23 Jun by Supratad