Numbering a statesman

WE BOUGHT a 2000 Holden Statesman International a few months ago and just love it. I know that when they were sold new they each had a number, and I believe a keyring was issued at the time of purchase. As we did not get a keyring with the car, do you think there would be any other way of finding out which number our car is? Holden told us that the cars were not numbered as such. We would like to find out for interest sake.