If yours is clean, you might be able to squeeze about £1400 - £1600 for your HDi.
Anyone selling a 2.0 Turbo, would be lucky to get £700.
I dont want to upset anyone on here, but they are hard to shift by any standards (petrol model, plus higher insurance).
I would sell privately then buy a Turbo if that's what you want. You'll be squids in!
