Thanks for answering my last question and all the other info I have gotten through MercedesSource by way of instructions and guides. I have new rotors that I aquired and the part number indicates that they go to the front of my 1984 300D. My question is that the old rotors (probably the originals)are bolted to the front bearing hub as you have confirmed. These new aftermarket rotors have no threads in the hub mating surface to accept the 5 mounting bolts that hold the old ones on. What gives? I have looked at other replacement brands also and see no way of fastening them to the hub. When it comes to brakes I don't want to mess around...it has got to be right!