I've been having problems with my clutch in my manual Skoda Felicia (1997) car. After (usually) some long drives the clutch fails to disengage (forever from that point on) and must be replaced. I had replaced the clutch for 5 times already in interval of about 1-3 months between each replacement. I'm no mechanic and the workshop tells me that it can only be the clutch, however, purely from statistical considerations this claim seems a little suspicious. After all, the first clutch lasted for around 10 years. Question is, whether the "purely clutch" explanation is viable or is there another problem at work here? If so, what would you suggest I can do to diagnose the problem?