Hi I'm in desperate need of the wiring diagram for the hk amplifier I'm putting in a new head unit, speakers, amp and sub but I can't figure out what goes where because there are 6 billion wires
in the h/k system

 

I don't know if this is of any, but maybe...
http://wtxmc.org/MiniCooperDocs/WIRING.pdf

Page down to the premium radio.

 

aw, i guess im a bit too late :( i was having the same issue and just figured it out. For others who were struggling I went by process of elimination, it's not too bad just don't over think it. There's a slightly thicker red wire which is the 12v line and the same sized brown wire is the ground. These two wires stand alone and are not bundled together, atleast in my r52. The 8 thickest wires in the loom go to the rear dvc speakers, so you can figure those out pretty easily. The slightly confusing part is the speaker level inputs. There's two pairs of them and the look very similar to the other speaker wires. The two very thin wires; one is the remote turn on and the other I think is to control the hk presets on the amp; you won't have a use for this after you upgrade the amp. Use a multimeter and check which is which. The most helpful thing I did was to hook up a small battery to each pair of wires and use a multimeter to check the voltage on at the other end. Then you can figure out exactly which wires go where. Ask me if anyone has specific questions, I still have my amp lying open so I can check and confirm wiring