I felt something as I applied the brakes after leaving from an oil change. I drove my car for two weeks thinking that if it was serious, it would get worse. The vibration stade the same, so I brought it back to be checked. Rice Toyota took it in and checked out the brakes, tires and volocity joints. They found the noise was due to the cupping of the tires making harmonic interaction at the speeds between 15 and 25, and at no other time. They also felt that the tires did not need to be replaced. I was not charged for the service call.