The letter of the NSW laws seem to only allow single lights (read centrally mounted light bars) if and only if you have 2 other additional lights: (from http://www.legislation.nsw.gov.au/fr...AND%20No%3D522 )
Quote:
89 How additional headlights are to be fittedIf 2 or more additional headlights are fitted to a motor vehicle with 4 or more wheels, the additional headlights must as far as possible be fitted in pairs."

