Ignition Question For Aftermarket Stereo

[Jonj1]

I have a MK2 Focus ST which has the oval Sony head unit it in it, I am fitting a double din Pioneer but I want to retain my steering wheel controls.

Connects2 has 2 interfaces, one for Vehicles without 12V Ignition Feed in Harness and one for Vehicles with 12V Ignition Feed in Harness. Believe the first one has something to do with can bus.

How do I find out which one I need? My car ignition has a key and the stereo comes on when no keys are in the ignition but beyond that I am at a loss. How do I know for sure what it has?

Any help appreciated