I got a fine and four points but no defect for having a ladder over my number plate on my 110. I went to court over it and got off the fine and points. Since I have stuck a nsw bike rack number plate on the front of the ladder and left the original number plate in place. I also had to illuminate the bike rack number plate to keep it legal.
So if you have the energy to pursue it you may have a good chance to get off in court.

