Sorry to disagree Blue Mk2, but thats a bit of a cowboy hack to solve the problem!!!
The reason you have two wires (one permananet, one switched) is so that the head unit will switch off when the ignition key is removed. By doing what you have suggested, our man will no longer have the capability to do that, as his head unit will be permanantly energised.
The reason he has this memory loss problem is because he has the wires the wrong way round, simple as that.
What you need to do is this;
Half way along the (head unit) loom you will see the red and yellow leads have bullet connectors on them. simply unplug them and swap them round, so that the wire that starts as red becomes the yellow one and vice versa.
This has the same effect as swapping their positions within the ISO block, and will mean that the requirement for permanent live is matched to the 12 volts from the car, and the switched 12 volts requirement is matched to the ignition live.
The reason this is needed is because car manufacturers and audio companies cannot agree on which position in the block should be which, so each manufacturer produces head unit looms that have the ability to swap the power over without the need for dodgy wiring hacks or connections.
