Hi, I'm having real problems trying to replace my Concert headunit with an aftermarket Sony headunit. I've tried the standard harness adapters that are out there on the web but have had not success so far, haven't even got power to the headunit as yet! I'm not exactly experienced with this kind of thing, but have managed to fit the same head unit into a BMW which I've just sold for an A4. I have a couple of photos here to show the wiring, any advice would be very much appreciated. Thanks.