OK, no thoughts, negative or otherwise re the rib, so I'm going ahead with the central position; started marking out this morning.
As I have a spare backing plate I'm not worried about minor errors, though hope there will be none! Intend to use the spare and keep the original to revert if the camera is ever removed.

A couple of observations:
1. My 4-rings badge isn't central! :mad: Maybe a couple of mm left of centre. Coupled with the odd extra badge (4.2 now removed) found when I bought it and the slightly misaligned S8 badge suggests repair work or at least a respray?
But with all the trim off I see no evidence of that. :Confused:
2. Decided rubber well nuts will be good for securing the camera as well, so looked at buying some more. Need M3 bolts to go through the mounting slots and ideally a shorter type than the 25/30mm version I used on the light.
Oddly, of all the combinations available the M3 type only come in that single longer length, but it will do OK so ordered a small pack complete with bolts.

I'll hold off on cutting holes until the well nuts arrive, I don't have enough at present.

The photo shows where it will be fixed, not quite taken square so the offset of the 4-ring badge is exaggerated a bit.
The larger circle (12mm min) will be cut out to feed the cable and plugs through with a smaller cut-out at the edge where the cable will sit when fitted (also allows a plug to pass a cable during fitting).
There's a single 3mm dia cable leaving the camera and a junction unit (max 12mm dia) about 500mm along then two 3mm cables (power and video) each with a 12mm dia connector on the end.
The slots are the holes for fixing screws, they will need 8mm holes behind for the rubber well nuts. The slots themselves are about 8mm long.
You can also see the location of the top centre fixing for the backing plate (just above the numberplate), conveniently slightly offset to the nearside.

I'm thinking to remove camera from my left side lens and install a new one in exactly the same location. But I wanted to find Audi OEM camera with a footprint that will fit that area. Following this thread with interest.

So the rubber well nuts have arrived, but are slightly longer/fatter than the ones I had. Just need to ponder that to be sure they're OK for the job.....

A little spare time today, a little progress. Drilled the holes, fed the cables through, inserted rubber well nuts and have a "first fit".
Not waterproof yet, I have a small piece of rubber to fit as a diaphragm then maybe add a bit of sealant too around the cable exit on the camera.
The use of the rubber well nuts means no concerns about steel screws into aluminium bodywork. :cool:

Pictures show close-up of camera from "below" and from directly "behind" at numberplate level. Surround yet to be cut and refitted; maybe tomorrow after testing alignment and a bit of weatherproofing.

Just a minor bit of trickery I forgot to mention.
The camera has identical wiring (but a different camera body) to that described in great detail by Steamship (Sean) in his thread, as pictured here:
http://forum.a8parts.co.uk/picture.p...&pictureid=568
You can see the thin cable I referred to and the junction "blob" too. The plugs/sockets (red and yellow) on the end of the camera cable are quite bulky so I trimmed them down with a Stanley knife so they fitted through a slightly smaller (10mm?) hole. Not least because I couldn't easily find anything bigger than a 10mm drill. :o

Angle of view from the "first fit" is looking good. Need to crack on with weatherproofing and trimming/refitting the surround.
The rubber diaphragm I intend to use behind the camera for weatherproofing is about 2.5mm thick so will allow for some fine adjustment.

Edit: diaphragm fitted, view just as good and minor adjustment possible by slackening screws. Also wired 12v supply into (N/S) reversing light - for reference brown is earth, blue/red +12v.
Tested fine, camera fires up and syncs within a second of selecting reverse. Now I need to start on the internal wiring to get the signal to the RNS-D.
But first, the surround, though it's just started raining here.

Been busy with the dremel; this is the final fit on the rear, though I may take it all off some time to clean up and improve sealing.
I half expected the lens to be slightly blocked by the plastic surround, but it's just clear - so no external trimming required, though I would probably have remounted the camera on thicker backing to avoid that.

Pictures of camera view, rear of car (spot the camera and admire LED reversing lights) and finally a close-up of camera from level behind (still see if you can spot it!).
Pretty pleased so far, "just" internal wiring to do now. +++

It will have to come off at some stage, the hole I "dremelled" isn't quite ideal. I tried to make a cutout to be an exact fit to the camera but ended up having to keep adjusting it.
The end result is now actually almost a 30mm by 50mm rectangle and is still a bit tight in places and ragged in others so I'm going to rectify that at some point and enlarge it slightly.
I'm also missing the top-centre fixing of the backing plate so plan to rectify that too; not quite sure how yet.

Looks a neat job HP. Are the lines adjustable?

Not on that camera, other than physically moving it. I've deliberately chosen to keep it low to see the bumper.