You will not know for certain unless its stripped down anything else is guess work.

My guess is that its either user error or the pressure plate is slightly out of line but why worry its lasted 4 years.

Carl,

It would sound as if the pressure plate has failed in the clutch assembly - this is not wear and tare issue its a progrssive mechanical failure,your clutch will gradually collapse. Mitsubishi will simply fob you off and hope you go away.

Personally if Mitsubishi have noted the fault at any of the service intervals I would write to their head office and advise them that you intend to have the clutch replaced independantly and recover your costs via a small claims court. The clutch on the Colt CZ1 is high quality and should last for 70000 + miles before it presents a problem,failure below this sort of mileage is indicative of mechanical failure it has nothing to do with your driving or clutch ware. I would have it removed before it fails and get a statement from the garage that does the work as to the reason for the failure and then summon Mitsubishi to court. If Mitsubishi have a clutch problem at such low mileage they should take reponsibility for it,presumably they try and dismiss these problems on mass to avoid callbacks. A number of Mitsubishi models seem to have suffered similar problems resulting in callbacks,the Colt CZ1 may be no exception.

Mark