Switched 12+ Wire on 2000 VW Golf MK 4

I Have been trying to locate the remote wire on my 2000 VW Golf MK4, with no luck so far, I have checked the voltage on each of the wires to try to find one which reads 12 Volts when the ignition is on for use with my amp. However, I find with the voltmeter that I find 2 wires (thick RED / White) Which are 12+ whether the ignition is on or not. The only wires I find which give a reading are a small blue and grey wire and a blue and white wire, which give readings of 6v each both only when the ignition is on. I have no idea which wire to use as the remote wire to my amp. I have tried the wires which come on with the ignition with no luck in turning the amp on. The amp works fine with a constant 12+ but this is not what im looking for. Having looked on the site I was unable to find which wires from any diagrams for my Golf.. or maybe I wasn't looking hard enough? I also searched the forums for an answer, again with no luck. If someone could tell me which wire to use as the remote wire to my amp, this would be helpful. Any help is appreciated, Thanks in advance, Steve

Many German cars have a barrier strip under the driver's side dash.  You can test the wires there- there's usually a 12 volt ignition source there.  Test and see.  No need to tap wires at all, just back out a screw and slide in your wire with a spade terminal.My ex once told me I have a perfect face for radio.