Early GTI's had the original cam lobe, which was made of a softer steel than the later GTI's. the cam lobes tend to wear faster and the cam follower for the high pressure fuel pump used to wear faster as a result.
Also used to have issues with the steering rack creaking, of which most were fixed under warranty.
Have a look in the maintenance section as there is a whole thread of what to look out for when buying a MKV GTI.
