Hi Paul, welcome to the forum

My 2p's worth, having only owned a GTD since July :-
DPF's and what they mean to re-mapping. ie. removal of, and by-pass pipe fitting etc for anything over 210bhp, just something to add into the equation (But Doc will put you right on that subject)
Your TT, did it have any kind of suspension adjustment?? If so you *may* want to look for a GTD with ACC.
Check the outer seat bolster on both front passenger and driver seats for water drip marks from top edge of doors, something I neglected to do but both my doors have leaked (are leaking? haven't had any rain for ages to tell!) and both bolsters are marked and will be bought to attention of dealer at service time.

Back to the DPF, I'll assume you do a fair bit of - shall we say - spirited driving,

therefore you should have no worries re regeneration of the filter..... but if you re-map the car, then you may remove it etc etc....
Good luck with your search
