My Audio Control EQS just arrived today, I want to install it on my 2002 X5. I am running an external amp and have disconnected the existing wire harness from my stock BMW amp.

I noticed there is a red 12 volt power cable and a brown ground cable going to the old factory amp via the harness. Can I extend these to use for power/ground on my Audio Control unit or should I attach power/ground to the same place as my aftermarket amp?

The chances of picking up noise are low so you'd probably be okay with using those wires.