Mike, there is some truth in this. My dealer told me that BMW was extremely unhappy about my car and the regional manager came down to the dealership to look at my car. And guess what, my car is on their black list. But I said to them that I am ok with them not warrantying items I have modded, but try not replacing an unrelated part and I will see them in court.
Taka, BMW Melbourne are very knowledgeable about their products. There is a difference between Mazda and BMW when it comes to servicing the cars. Also I am not sure if you realise that the dealership you bought your car from is effectively BMW factory as the dealership is owned by BMW Australia which is a wholly owned subsidiary of Germany. So they train their technicians really well and send them to Germany etc.