What other 18" wheels (Jaguar or other manufacture) will fit on an x-type sport? I was going to go to our local salvage yard to look. I would like to find one to use as a full sized spare.

 

Heres a list of other vehicles with the same PCD - 5x108 - Bolt pattern - Wheel-Size.com

But you will have to bear in mind the offset of the wheel, as not all of them will clear the suspension on the X Type.

If your going to run a 7.5x18 wheel, you will need an offset of at least ET52.5
If your going to run a 9x18 wheel, you will need an offset of at least ET43

 

They're likely to be heavier so will reduce performance & handling and will increase suspension wear (perhaps dramatically).

If in UK be certain to tell your insurer (mandatory, else they can void your insurance).

 

We don't have many of those vehicles here in the US but it looks like I should be alright using a Ford/Lincoln wheel.