I have a question concerning a Contour brake hardware piece. What are the intended purpose for the little metal bushings (almost look like a lock washer type of device) that go around the lug bolts, located between the rotor and the wheel? I guess the obvious answer is for holding the rotor in place with greater stability. However, I did a brake job this past weekend and went out to the auto part stores to look for some of the metal bushings. But, none of the stores had the correct size to fit the Contour lug bolt. They only had one size greater and one size smaller. So then I went to the Ford dealer today to ask about getting some of them. However, the service man said they don't even stock the little metal ring and they can't be ordered. Then he told me that they are not really needed. To verify that statement, he went out and got a service technician. The technician kind of laughed about it and said they are useless. He said they are unnecessary and are only used to hold the rotor onto the car when they are being made on the factory assembly line, thus that the rotors don't fall off and hit a worker. So my question is, are these little metal bushings/lock washer type piece a necessary part of our braking system or are they simply a useless piece that only has relevance on the factory floor?