Hi Grahame,
I also like Steve, used a bit of wire.....an old coat hanger wrapped around the flimsy rubbery aerial......definitely not heritage listed....lol
Travel safe!
I too just used a piece of old Telegraph wire that I found along the Oodnadatta track 5 years ago. Its about 1m long. It works a treat and it may even be heritage listed ........... cost - $0
This link may be of assistance- http://www.rta.nsw.gov.au/registration/getnewrego/interstatevehicles.html An indicator that an interstate registered vehicle is permanently garaged in NSW is the vehicle has been in NSW for more than three months.