I was looking at the inside of a 1978 Buick Le Sabre and noticed the dash layout looks very similar to the Australia HZ Holden Kinsgwood's of the same era late 70's. The steering wheel looks very similar in shape also. I would have to guess that although Holden is Australian they shared a lot of ideas with GM in the USA. And made subtle changes.
http://www.autabuy.com/Vehicles/Details.cfm?VID=507611&Year=1978&Make=Buick&Model= LeSabre