Welcome to the Forum Adam!
I've got a 53 Plate (December 2003) Grand Priv 2.0T (Petrol, couldn't bring my self to buy an
Burner, but I may do next time after seeing how much this baby drinks
I'm with Lag about the warranty - I wouldn't risk running one without. I bought mine when it was 8 months old so I've had the benefit of a couple of things being sorted on warranty. Later this year I'll either trade it or buy the Harmony warranty.
Don't know about them changing in 2005 but there's nothing wrong with the handling - they are a great car!
Any specific questions, just ask!