One problem related to clutch pedal/linkage has been reported for the 1999 Mazda Miata. The most recently reported issues are listed below.
After driving at highway speeds for more than an hour, if I stop the car, put it in neutral, and take my foot off the clutch, I hear a loud rattling noise what sounds like a bad release bearing. When I press the clutch pedal to the floor, the noise stops.