There are some mounting bolts on the floor, and people have come up with a variety of brackets to use these. Mine is a steel SHS offcuts cut to suit:

Wiring is simple, as Ineos prewired this location for a compressor (Fuse 113).

There is also just enough room to fit an outlet and switch, tucked behind the seat support. I used the ARB mounting kit (slightly cut down) and a backing plate for strength. This gives access even when your backseat is packed with your partners essential luggage. Nice and tidy!

Yes, it does get warm if you use the compressor a lot. Probably not the best location if you are airing down and pumping your tyres up all the time, but not an issue for the infrequent user (such as myself). Or you can open the seat base up to provide ventilation… whatever works!

Another small piece of composite, attached to the back of the RAM mount I use for a tablet, and I had somewhere to mount the headset for my VHF as well:

Many of the little screws are just for show BUT you do have to take off this panel:

Then you will find two black screws to remove:

With them out the way the whole panel can be unclipped, nicely hinged at the front. Voila!

As most know, the Grenadier comes pre wired with several useful circuits for owners to play with. In the passenger (left) footwell there is one such pre-wired point. Switched by the INT 1 switch in the overhead panel, fuse 129, 10 amps.

You will find the wires looking like this, taped down with plastic inulated tips:

Wire up to a deutsch plug to future proof the connection:

Smilarly wire up your prefered USB sockets:

And there’s a little metal bracket you attach a longer bracket to (photo taken looking upwards):

And the end result looks like a bought one:

Hey folks – this is the final solution for my internal bike rack. It worked out a treat.
The only downside is that my Road Bike needs the seat removed. My wife’s bike was fine and my Mountain Bike has a dropper seat post so no issue for that.
Another thing to note is that due to the stem on my bike being pretty long, I had to span the middle pillar of the rear door. So the hoods fit nicely into each of the window recesses (basically that spot for my bike (sliver one) is the only place it would work and still allow me to shut the doors – but who cares, it works!!).
Finally, for the MtB I had to swap out the other fork adapter and spin the mount 180. That bike is longer and I needed the extra space that is not taken up by the drop bars of the road bikes.
It is 100% solid and those bikes are going nowhere!
This is what you need…
1 – Loaded Bikes Rail (Short 1138mm length – I also needed to drill x2 6mm holes in this – see pics for where to do that)
2 – Loaded Bikes Fork Mounts (x2)
3 – M6 T-Track Adapter (you need to order M6 washers and nuts separately)
4 – Loctite Red Thread locker

Ineos have Grenadier seat covers as an optional extra, but initial reviews have been somewhat negative with a less thatn perfect fit and appearance.

Melvill & Moon offer an alternative, shown below. Melvill & Moon are “Safarri Outfitters” and have a really interesting range of other accessories that are worth a look. Who doesn’t need a set a filleting knives? Of more relevance they have dash mats for the Defender; so keep an eye out for the Grenadier option.

Here’s an installation of a Blackview camera system (BlackVue DR750-2CH LTE 4G Cloud-Connected Front/Rear Dash Cam with 32GB microSD Card) by Bell Auto Services – with front and rear cameras. The system has cellular connection and stays on all the time – so images are stored on the cloud and can be viewed when away from the vehicle. A nice tidy solution giving extra security.

This camera setup was wired to the CTEK Smartpass 120S on the dual battery system, so draws power from the Service Battery on the “Consumers” output, so that the Battery Guard can turn it off as a non-critical device if the Service Battery power is low.

Expedition HQ has a range of UV block-out shades provide privacy, internal heat reduction, and eliminate natural light inside the cabin. They’re available individually or as a complete kit, so all requirements are covered (pun intended)

Update 24/5/2023. Blickdicht (Germany) have released a range of high quality interior shades. Available in a variety of colours these are multilayer and excellent insulation. There does not seem to be one for the Safari windows, but all other windows are catered for.

(thanks Mark Durrant for the contribution)