I've never understood those plates that are off to one side. Don't they cause the car to pull to one side? They also look plain wrong there.
Pretty easy to understand: I didn't want holes drilled in my brand new car.
Here in the USA (probably in Canada and Mexico too), the cars come with a license plate bracket for center mounting but it requires drilling two holes in the bumper. I'm not sure how it works in Europe and Australia with your wider plates.
Tim