C-max, Car audio stuff seems to make mountainbikes look ‘standardised’. Mines ended up with about 2ft of addapters to plug together.
Stereo -> something (ISO maybe) -> something -> steering controll addapter -> little black box -> steering controlls.
I’m actualy worried that all that isn’t going to fit behind the dash!
I asked a shop on ebay (liquidice-2008) what to get and they priced up a kit with all the relavent addapters so it should all go straight in, assuming the stereo itself fits, the mounting doesn’t need reinforcement, all the wiring is correct, and I’ve not yet found anything in any of the boxes that resembles the earth lead from the instructions!