Just a few links that could be usefull.

ARA Car Rental 
86 Belford St, Broadmeadow NSW 2292
Tel:     +612 49 622488    or     1800 243 122 (within Australia)
Fax:    +612 49 622263

129 Melbourne St, East Maitland NSW 2323.
Tel: +612 49 345033
bookings@ararental.com.au