I just installed on in my 2008 Safari. A wired camera all the way to the monitor, so power is from my TV. I mounted it above the license plate., drilled a hole thru the backouter skin and then another one thru the inner skin. This is inside my bath cabinet, then around under the toilet, under the kitchen sink, furnace, frig, and into the closet on the curb side. I just had to do a little fishing to there. then the amazing thing was to get it out and to the hitch. Well, there is a 1/2" hole from just back of my A-Frame in the cross beams. Luckilty I found it and your may have the same. Well I fished a 3/8" wooden dowell thru 3 holes in the cross beams and low and behold, it came out in the water pump access. I then used the dowell to guide a 1" Sch 20 PVD pipe thru to there for protection the camera cable. used a 45 deg elbow to finish it off on the underside and then ran the wire to the hitch. I have the same 4 or 5 pin plug for the camera.
Maybe your Cloud has this same hole in the crossmembers that you can access. It made my job a lot easier to exit my AS.
I was advised against the "wireless" as there is tooo much interference.
Or check for the hollow frame as per Splitrock. That should run front to back.
Why do you mention the rear tail light fixture? will you remove it to place the camera or just to get 12 volt
power for the camera?