Quite simple really...
Raw only supply something called a Universal-loom from which you install in your striker. Sadly the company which made this loom has gone bust a long time ago. There are no diagrams, aside from, roughly, 80 pieces of A4 with various bits of wiring on which the previous owner did.
Furthermore, where things have been cut and chopped around one colour goes into the wing and another colour comes out. In turn, each wire will need replacing as most are too short, too tight and poorly crimped.
Having come from 3 Mini's I'm more than qualified to say that I know what a poorly wired loomed will mean for the Striker and in all honesty, with this years season almost over I don't want to spend big parts of the new year struggling to resolve electrical problems.