About 3 years ago I sent off a suggestion to the NSW RTA that since USA sized plates were an optionin QLD, they should look at it for NSw as there were numerous US sourced vehicles that had issues displaying Aussie plates - I use black/white two letter-three number plates that fit fine, I luckily bought them before they became a "rental" proposition.
They emailed me back saying they had referred the plate size to the Police for checking that they could be read by photo ID equipment....still no plates three years later...but they can issue standard sizes in every ugly colour under the sun, incuding footy club colours.....thanks for consideration, guys....