[plymjack]

Yes its hard to do the maths but the % discount is large so worth considering, X3s are in short supply and a well spec'd one will certain hold its value, so as Phil says if get that one you can still trade it in for you spec later....

cc3 makes a point but since you were amending a previous order I think you might struggle to push the dealer to give you a car for a year for nothing, so you would need to still do the maths if you can get a fixed trading from them.

Good luck, let us know what you decide.