I am quite sure you can claim car expenses as tax deduction, if you used your car for work-related purpose. For example, if you used your car to travel from one work place to another work place. The deductible amount can be calculated using one of the four differenct method as per ATO.
I would suguest you to keep a log-book for the work-related use percentage, and keep records for all motor vehicle expenses, i.e. petrol, rego, insurance, repairs and maintance, etc.