Bye bye old Kenwood and OEM Hitachi speakers with disappearing surrounds (and disappeared foam baffle). Thanks to Andrew for previous posts on this subject (I'll add later if my bookmarks worked) and the adapter rings.

So that's:

1.  replace shot speakers with new JVC, new foam baffle,  get rid of speaker loom bodge at head unit end and speaker connection end (re-instate OEM)
2.  get rid of head unit wiring bodge by repairing cut/connect and using proper ISO adapter
3.  add dabonwheels Kinetic DAB / FM aerial adapter
4.  Install new JVC DAB/CD/USB
5. mount ECUTalk in cubby
6. mount USB socket somewhere
7. install underseat subwoofer
8. test

Play Radio 3 very loud ? (oh alright, AND Planet Rock and Radio 4 Extra)

Good luck Mike....!

Looks like I have the same type of USB socket as you; I mounted mine inside the centre arm-rest storage area

Good luck with the installs Mike ?

How did the installs go, are you happy with the underseat sub? Was thinking of getting one of these as the OEM one that came in my old 3 series gave a nice sound.

Just trying to avoid taking up too much space in the boot with a sub (don't want anything booming but the Z's normal speaker configuration doesn't give enough bass for me)