However, this system was not as popular as expected: the Northern Territory refused and continued its previous all-number system. Western Australia soon adopted the scheme, taking charge of the previously NT allocated XAA-000 to XZZ-999 (WAG-000 to WAG-999 they reserved for WA Government vehicles, then extending to XZZ-999). However many WA rural shires chose to issue their own series plates, with initial letters being Shire abbreviations followed by digits, in the WA colour scheme.
Queensland, after initially skipping the O-series (as a capital-O was often confused for a number 0), were left with too few combinations for a growing number of registrations. The Q series plates were reserved for Qld government use. In 1978, having exhausted Nxx-nnn to Pxx-nnn combinations Queensland reversed the format, starting at 000-NAA continuing through to 999-PZZ in 1987, when plates commencing at 000-AAA were issued. Colours were white reflective background and green lettering (later maroon).(There are still a number of vehicles in Queensland – growing rarer as new cars and new plates replace them – with the old white-on-black Q and six black on white digits at this time. Only one of these was issued, for display at the rear.)
All the remaining states and territories stuck to their initial allocations, until the number of registrations became too large for each state and were ‘overflowed’ into other series otherwise allocated to another state: NSW overflowed from FZZ-999 to GAA-000 (otherwise issued to Victoria) in 1972, Victoria (having reserved the Mxx-nnn series for State government registrations) overflowed from LZZ-999 to IAA-000 (previously skipped) in 1974, and then from IZZ-999 to AAA-000 (otherwise issued to NSW) in 1977. South Australia did similar, overflowing from SZZ-999 to UAA-000 etc. (having reserved the Txx-nnn series for trailer registrations). Would you like to get more info? Then do not heistate to check this California license plate lookup tool to obtain detailed data.