Ok, this mod does work. I've got a 2006 Omega and I've installed a headunit from a 2008 Maloo, which is the Calais headunit that is also in the SSv.
You can buy it brand new now:
COMMODORE VE SS-V RADIO CD UPGRADE SUITS SS SV6 & OMEGA - eBay, Other, Car Parts, Accessories, Cars, Bikes...