The 924S, 944, 944S and 944S2 each featured a rubber centered clutch disc from the factory. Generally, when the clutch fails, it won't be because the disc ran out of friction material, but rather that the rubber center deteriorated and fell apart.

To check for rubber center failure, lift the car and be sure the clutch is engaged (at rest) and the transmission is in neutral. Locate and pull the trapezoidal rubber plug from the front-bottom of the transaxle bell housing (just in front of the transaxle.) Reach inside and grab the drive shaft. Attempt to twist it by hand. Any more than slight movement (<1 degree) is usually an indication that the rubber center hub has failed.

In failure mode you may experience shuddering on acceleration and extreme lash on deceleration. The lash is a product of the built-in failure mode on the clutch itself. When the dampening rubber is gone, the clutch will rotate approximately 1/6 revolution until it engages metal cogs. The metal cogs are there to give you a "limp home" mode after failure. In some cases, a few thousand miles have been gently put on a car in failure mode. This is not recommended.