My ten pence worth...
When you test drive it listen really hard for bumps/crashyness/rattles to try and get a feel for how sturdy it is. The big jobs looming up that I would factor into the price at that mileage are...
1) Turbo will prob need replacing soon-ish.
2) All suspension bushes (lots of labour) and poss the suspension itself.
3) Might seem weird, but the sports seats might be getting either tatty or squeaky, which got irritating on mine.
Also, as for price, £4600 is quite a lot, unless your getting a really decent warranty? The other thing you need to consider is that with another 15,000 miles on the clock, its going to start getting pretty hard to sell on.
Just to give you an idea, I just sold my 80k 1.8T for £4,100 (could have got a bit more, but I didn't want it to hang around too long)
