A twin Turbo AWD Falcon was already done... as a protoype almost 18 years ago.
Check out the pic I attached of an Article a little while back.
There were 3 prototype's built with one being written of in Oz, one written off in England, and one being rebuilt in Melbourne, of which the owner has a spare AWD running gear from one of the wrecked proto's.
This is what Ford needed to challenge the VL Turbo's and the Skyline's, but it's wierd how the Aussie car market works...