It's a weird connection that is by itself on the annt side of the original deck on a e36. I cut it peeled the insulation off then wired my annt power wire from the head unit (could use amp turn on if you havn't got one for the annt) to the solid copper part.
Could be the same for an e46.
"They say ignorance is bliss..... I don't know what the Fu*k that means but I'm pretty happy". Ricky Trailer Park Boys.
Current Mods....X-Brace, Stromung Cat Back Exhaust, 17/225/45 M3 Replicas, HotBits Adjustable Coil Overs, 40% LSD 3:91 Diff, E30 Gearbox, Boosted.