Quote Originally Posted by DDT
But aren't you just making an assumption that the word "truck" is an "American" word in the first place? or "trunk" for that matter?

What proof is there that Aussie english is even 'drifting"? Even in the early 1960's most people used the word "truck" in Australia.
I submit to you that all these words are of English origin.
'Truck,' describing a road vehicle for freight, has its origin in America—even the obscenely Anglocentric Shorter Oxford English Dictionary concedes this fact. The Australians borrowed the word in that meaning from the Americans.