HI
Thanks to all the great info on this site I have been able to install audio steering wheel controls successfully into 2.5i sedan without too much difficulty.
Note no extra wiring was required to Model GX-204KHF2 standard 6 stacker CD unit as requisite wires were included in factory wiring.
Controls cost me $50 from wreckers in Sydney.
Mod was well worth doing - as someone else said, this was an essential feature that Subaru should have made standard.
NB some models MY10 Forester also have identical steering wheel controls
Cheers