There are actually springs under the rubber - the rubber is more like an absorber for any kind of vibrations which the springs might cause. What I don't know is if it is double spring design or not. Which is not that important imo because I don't think there is a single manufacturer who produces such clutch disks anymore, or at least I am not aware of it.
What I forgot to mention, is that the OEM 'rubber' clutch (besides the Nissan stamp) has the UNISIA sign on it.
jagy - I didn't say anything about the tranny