Miatas are GREAT cars. And I do mean GREAT. Their owners know that there are very few problems that come along with Miata ownership; but there is one small weakness in the clutch slave.
The Miata clutch slave will develop a leak over time and most people do not even know that it is there until it is inoperable. You can see the sign of a leak in the clutch master cylinder reservoir(container on the right in the first photo below); it will become low for no apparent reason and you may even need to add fluid over time. You see, what is happening is that the clutch slave has began to leak in to the boot(see photo below). Since the boot is a somewhat tight fit it contains the fluid and therefore you don’t see any spots in your driveway or other signs of leaking. This is a relatively simple repair and doesn’t cost a lot of bucks but if you have noticed any loss of fluid from your clutch reservoir you should get it checked out before it leaves you stranded.