I think its worth looking at an approved used MK6 GTI at this team of year from VW as they are doing good deals (end of financial year approaching). I just bought mine from a VW local to me. I saw the car a month or so ago and thought I would let it dwell for a bit until they knocked the price down slightly which they did. I ended up getting a further 1k knocked off and had an extra 2years warranty 2 years servicing, 6 months tax, some nice new mats and a full tank thrown in !
Its worth the extra premium to go through a dealer IMO as it makes it just that bit more hassle free (doubt everyone agrees).
Ive had a few niggly bits already which have been sorted already. They guys at my local dealership are really nice chaps and surprisingly helpful.