are you talking GT or GT line ?
go diesel, if they are going to keep it for a while they will save in the long run, not may faults, just what martin has listed really, my high level brake light failed but most of them may still be under warranty so they should be okay, bolster wear i found is quite common so check for that, warranty also will sort that, difficult to find with alot of optional extras many are low spec, also the laquer on the wheels tends to bubble if they havent been looked after that well,
but overall the engine is really smooth and quite and great on fuel as it comes with the 6 speed box, and imo they are the best looking out of the non sports