Just to follow up on this, I went back to it and drilled a little deeper into the menu options within the ehc section and found a "disable trim mode" option, so whatever it does it's now disabled.

Whilst there I discovered the hand adjust menu and thought this is where I needed to be to get her level, although I can address each corner and make it move up and down, I am not sure its behaving as it should. raising the left rear by 10mm also seems to raise the right by around the same.

Is there a guide anywhere to help with this? A bit of searching suggests INPA isn't up to height setting which seems a bit odd as it definitely seems to be able to address the air bags.

I need to replace the subframe bushes soon and can't help thinking that it may be worth putting springs on the back and losing the air, but not sure I want to live with an error message popping up everytime I use the car as I understand its not easy to lose that message once the conversion is done.

Any pointers would be great, thanks in advance.