Hi Mate check out this product on ebay http://www.ebay.com.au/itm/STEERING-WHEEL-CONTROL-HARNESS-Toyota-Camry-Aurion-/250774652015?pt=AU_Car_Parts_Accessories&hash=item3a6355846f
Looks like if you buy an aftermarket head unit which has steering wheel control capabilities then this unit will enable them to be used.
Good luck with it and post some pics up when your done
Cheers
Peter