Hi
I have the base 660 radio cassette in my GS Discovery 2. If I fit the steering wheel remote buttons will they control this radio?
Steve

If as you say you definitely have the "base line" set up then probably not.
In the diagram of the steering wheel controls, the two wires, grey/black and grey/red are marked as "mid-line".
The two wires might be present, LR would normally fit a single type of wiring loom across a number of different variants of vehicles.