10-12 k covered in mine since Jan. AWESOME. look out for:
1) Anything you would look for when buying any car and look at this for an idea of specifics: Alfa Romeo GT Buyer's Guide
2) EGR - you can strip, take to pieces and rebuild yourself - easy DIY. I am not handy with the spanners and I managed it.
3) Suspension - Not the best and tends to wear easily - I have 18's and I wish i could try 17's.
4) Driveshafts - Wear in time but easy fix, usually with a spider joint - £60 part and hr or 2 labour.]
5) Dual Mass flywheel - is it wearing? pretty pricey.
6) Doors - Are the straps clicking? Easy DIY fix but the straps are pricey at £40 each.
7) Master Cylinder can break
8) Don't get the JTS - I have been told that it is not the best by 3 different indies
9) Obviously, waterpump and cambelt - as you will know.
10) Oil Cooler Pipes - How crusty are they? The pipes will need changing as will the rad that they go into which can be pricey.
Now some generals. There is the JTD and the JTDm. The m stands for Modificata. There is no real difference but the JTDm is supposedly slightly more economical. This means a VERY SLIGHT difference in tax I believe - IT DEFINTELY MEANS A SLIGHT DIFFERENCE IN INSURANCE, with the JTDm being SLIGHTLY less. 06 engines onwards have a different inlet manifold. These can also cause issues. I have a 55 plate and I have the 06 engine with the old inlet manifold - a good little set up i have been told!! I think they stuck a DPF on the later engines too - at £2000.00, I am happy that mine does not have one fitted!!!
Just be patient, and have a look at a good few. I am certain you'll pick a good'un and have as much fun as me. I cover 120 - 150 miles per day and travelling around is a pleasure now!!!