i'll go with what Chinese Alan said. if you fancy a diesel, do not go for a test drive in a V6, there's no way you aint buying one if you do. Mine costs me the about £450 a year tax plus insurance plus fuel, but I don't drive it so much so that's cheap motoring compared to a new car.
It is so awesome every time you go in it. i got home from work twice this week, got the keys out and just sat in it for 5 mins thinking how awesome it is, I love the cab. You then see in the GTA thread where some guy has painted his cam covers black and you start getting horny.
Get a V6, what's it going to cost you? 10-20 quid more a month? You'll spend a lot of time time tapping your steering wheel, talking to your car and laughing at how good it is, you'll feel like you're going mental. You don't have to drive it at full pelt either, just putting your foot down is awesome.
The V6 Gt is undateable, it's a car in it's own right, barely facelifted and so practical with the fold down seats. I know the diesel goes incredibly well and is the sensible choice, but V6, omg!!