Hi Pauline,

There is a known problem with the clutch assembly that causes rattling and yes, it would be expensive to fix. It doesn't affect all examples of the car, though, and if it has been repaired already with new parts then it should not re-occur. 

In terms of the engine, it is known to develop turbocharger problems (a high-pitched whistling at low engine speeds is usually the give-away) and oil leaks from the head gasket. Both those issues are expensive to fix so have any car you're thinking of buying checked specifically for those problems by someone that knows what to look for.