CHECKLIST FOR YOU
Step 1
* Check to see that there's no clash of dates with anything big in NSW/ACT
Step 2
* Insurance advised so you don't get sued. SAU.NSW is able to apply to CAMS for insurance; but the Event may need to be run officially by the Club
* Disclaimer statements checked by a solicitor
* If part of admission goes to charity, some charities have strict conditions eg Beyond Blue
Step 3
* "All Japan Day" organisers from SA hopefully won't have an issue with you about naming your event, "All Japanese Car Show". Might be best to check with them.
Step 4
* Organise a team of helpers who can take on the responsibility of various roles/chapters
* Have set meeting dates for team members to report
Step 5
* Venue and date set in stone
* Plan B required perhaps in case of rain
* Choice of venue near toilets
* Venue requires electricity
Step 6
Roles/chapters include...
* Food/drink eg CAFE2U, your own drinks tent/marquis
* Marketing eg SAU, Facebook, Canberra Times,
* Publicity Coverage eg Canberra Times, Performance Imports, Performance Garage, Motive DVD
* Cold calls to Car Clubs setting out commitment dates
* Sponsorship eg Trojan
* Stalls
* Aftermarket products eg shirts advertising the event
* Tickets accounted for on spreadsheet
* Payment methods
* Refund procedure
* Your own photographer or videographer if unsure about magazine presence
* Certificates of Appreciation to Sponsors
* SnS trophies if there's a competition
Sounds like a great idea
It looks like you're already covering some bases.