The NSW heritage number plate 400 is said to be owned by well known automotive identity Bill Buckle.
It has been spotted on an Audi R8 and a Tesla Model S.
Tesla Model S – 25 September 2015 – Heritage Number Plate Spotting
Audi R8 – 4 September 2014 – Heritage Number Plate Spotting
If you have more information or photos of NSW 400 please let us know.