Update to my thread, as I've got a bit of time on my hands at the moment !
I decided on the Grom interface option, rather than a replacement head unit, as I only really listen to two radio stations in the UK and listen to music from a USB device, which is what I would listen to on any Euro trip. I also included the Bluetooth interface option as well.
Installation, pretty straight forward, just remove the centre console and associated units, found a place to mount the Grom unit and wire in the phone microphone next to the rear view mirror.
I could've done the whole thing in one day but the Mrs suggested that I might want to drag the job out over a few weeks, as the chances of getting the car back on the road for the beginning of April, was not going happen. So the job was started a month ago and finished this morning.
Attachment 13883
Mounting the Grom unit.
Attachment 13884
Attachment 13885
Routing the wiring for the microphone.
Attachment 13886
Attachment 13887
Testing the USB.
Attachment 13888
USB connector in centre console.
Attachment 13889