hi
ive not long had my 18t and its great but have to agree with everyone else, it is underpowered and very thirsty.
a freind of mine has the 2.5 v6 tdi and again not very powerful nor economical so i guess the 3.0 v6 would be a good option, i didnt go for one due to running costs and what seems to be greater depreciation on the 3.0 .
on the later model i think they now do a 2.0 tdi which might be worth looking at.
despite all the slating of my own car i still love it, its a very well built smooth classy car and will get the later shape next year.
good luck in getting one, its the right time to buy one as they are very cheep this time of year.
which ever one you get im sure youll be happy with it.
lea