basic CD400 looking for more

[Rusty2009]

As Vocky has said you will need the following.

Navi screen (depends what Navi system you want to fit as to which one).
Navi screen surround (which one depends on if you sport/tour VXR button).
Navi control panel (the 600/900 650/950 will all work with whatever unit you fit).
USB plug USB cable (I make my own when installing).
Custom loom for the wiring changes (again I make my own).
DAB module (again depends on what navi you fit as to which one).
BT module (unless fitting a Navi950).
GPS aerial I most fit hidden one's unless customer wants to pay more for a roof one (unless it's a GTC with a dummy shark fin).
DAB aerial, can use a window one or aftermarket roof or factory.

Unless you have almost £2000 to spend on a MDI are willing to pay the GM sign up fee's and can prove your a businesses & your willing to pay the hourly fee's to be able to program forget trying to program yourself.