When I had gone under the car to change the transmission fluid I noticed that the bearing balls were exposed in the bearing - in fact half of them were missing. I had just finished a 300 km trip and there were no signs - no noise, no vibration. Took the car to a transmission shop and they managed to remove the bearing without taking out the tranny. Mechanic said that they had never had to replace one of these bearings before because no one had ever noticed when it was gone. Most people drive the car until it ruins the transmission and the whole thing needs to be replaced. So obviously this is not an isolated instance...