hehe that's where I bought my car :D, their customer service is great but I moved over here before I looked into getting the problem fixed, and still haven't, oh well, soon... Also NEVER go there for an after hours service, all the service managers are not there during that time and the lackies have no idea what they are doing other then changing fluids...
I don't know about the other dealers in Sth Aus, maybe try CMI on West Terrace or the Lexus place just down the road.