How bout going through some car forums and getting details of sydney performance car work shops, and cold call!
Send some emails, go see workshops in person, give them a call etc.
Prob best to call in, with your resume etc so they know you are serious.
I did that a few years back, when I was greenkeeping I wrote to alot of golf clubs and went in to see a few managers,
Some didnt even reply, but one was happy, and gave me a job
Good luck,
Cheers!
Chris