Where is it hiding? I spent all day stripping the car down believing it to be behind the dash. Can’t find it anywhere.

Book says on the cross-rail, behind the instrument panel on the passenger side. Photos attached show where it should be (flipped from LHD to RHD) and what that looks like in my car.

2016 Autobiography 4.4

Click image to enlarge

Click image to enlarge

Going by the picture, it looks like it should be behind the metal facing us. I.e. you wouldn’t be able to see in that second picture. It’ll be behind the bar ??? V8 or else ...

Exactly, but it’s definitely not there. You can even see the loom runs a different path to what the book says too.

Mine was tucked up there it's almost impossible to see you have to get upside down and look in and its behind a metal bar/piece.
Whatever problem you're chasing though, it is unlikely to be this module.