Options for a reversing camera

[HPsauce]

Another bit of mental gymnastics that might help anyone else thinking of doing something similar, i.e. fitting the camera above the number plate.

The plastic backing plate, as noted above, is fixed with a few screws and the numberplate lights are fitted separately (and tightly) directly to the metal boot lid, presumably to keep them watertight. The plate itself is not sealed around the edge (though someone here has done that) so water can, and will, find it's way behind it.
Even if sealed all round the edge sprayed water can enter around the numberplate lights, there's a significant gap there.
There are small sealing discs around each fixing screw location because of that. I suspect degradation of those (mainly the larger two for the two big numberplate screws) is probably to blame for the water I get inside the boot lid, so I'll renew all those when I do this job properly.

So, I'm going to mount the camera on the plastic backing plate, ensuring it is as waterproof as possible - the cable entry isn't clever so I'll seal that. But if there's a hole for the cable I won't worry much, though I may put a grommet on it.
But beyond that I'll concentrate on providing a new waterproof entry (grommets, sealer etc.) for the cable through the metal behind it, making sure any connections are behind the seals I use.

[HPsauce]

Originally Posted by HPsauce

So, I'm going to mount the camera on the plastic backing plate, ensuring it is as waterproof as possible

Or maybe not.....

Looking again at how the numberplate lights are fixed directly to the metal structure of the boot lid, I'm very tempted to do the same with the camera.
It will make sealing against water ingress easier, and adjusting the position precisely for the best view. Wiring will be simpler too.
Finally, a hole will need cutting in the plastic numberplate mount so that it fits over the camera, but that will be easy enough.

[HPsauce]

Back from holiday and the weather this week looks good, so I've started preparing and planning....
- Removed boot lid liner, carefully storing/labelling the fixings (2 nuts and 3 different types of screw)
- Removed number plate and backing plate.
- Plugged (rubber bungs) the 5 backing plate fixing holes and refitted number plate - luckily had some identical but shorter hex head bolts to do it neatly.

Started examining and thinking about holes for:
a) camera mounting and lead
b) emergency boot latch release

The top centre backing plate fixing is slightly offset to the left/nearside so the camera will go slightly right of centre. Needs to clear the backing plate central "rib" and obviously the right-hand number plate lamp - plenty of room in between, about 3".

The emergency release I'm considering something as simple as a piece of nylon cord (even a cable tie?) directly attached to the release lever on the latch, adjacent to where the actuating rod is connected. That overcomes any possible failures in the linkage and/or joints,
That cord would the run to the right/offside (it moves that way to release) and be fixed to the back of a bung in a small hole in the boot lid metal, with a slightly larger hole in the backing plate.
Then to open up, remove number plate, lever out anonymous-looking bung and tug on cord

[HPsauce]

Work keeps getting in the way, but having fixed the broken numberplate light this morning I did a test fit of the camera in its exact proposed position.

Horizontal angle looks good flat on the metal, but ideally could be a degree or two higher (as adjusted in the picture below using a sliver of blu-tack).

There is no sealing material supplied so I plan to have a thin layer of silicone sealant to cover the cable hole and sit behind the camera sealing its cable exits too. That will allow the very small amount of vertical and horizontal adjustment needed to get a perfect alignment. There are also a pair of fixing screws which go through slots not holes so there's plenty of "slack" for last minute tweaking.

Hope to start cutting metal tomorrow; don't want to start today as I need to use the car later. Still pondering the emergency boot release option(s).
Also need to replace the boot opening seal while I'm at it; it's damaged at the sill. That will probably happen once I've worked out the video cable route.

[HPsauce]

Originally Posted by HPsauce

The top centre backing plate fixing is slightly offset to the left/nearside so the camera will go slightly right of centre. Needs to clear the backing plate central "rib" and obviously the right-hand number plate lamp - plenty of room in between, about 3"

Then again, maybe not? There might be a better solution.

Looking at the plastic backing plate again I see no reason why the camera can't actually be totally central. There's plenty of space behind the metal to allow that.
The only (minor) issue is that the plastic backing plate has a sort of "rib" in the centre, directly between the two numberplate lights. It doesn't seem to do anything except maybe add a bit more rigidity to the moulding, but that seems unimportant.
It will mean cutting out a tiny bit more plastic but that's hardly a problem. And in fact the way it's shaped may actually provide a better, more easily sealed, cable exit route.

Anyone have any thoughts about that little rib?

[HPsauce]

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! 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.
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.

[notorious]

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.

[HPsauce]

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.....