Thank you for the suggestions. My preference is for nearly new, ie. less than a year old, ideal would be ex-demo, 1000 miles.
Not keen on German sports cars - too serious, too sensible and too common, all bad qualities in a sports car. Just my prejudice, don't want to argue.
Aston Martin, Maser - no, don't want to spend that. Also would look silly outside my 3 bedroom house.
Old cars - Can make sense, but don't want an old car.
Exige - requires own race track, which adds about £ 10 billion to the cost.
Evora - Too tracky, plus I could have a GTR for that.
Jag XJR - Cool, almost sub zero but they are asking Mustang cash for 20,000 milers. No ta.
Jag F-type - awesome sound but poor VFM. They want 55k for the 370Z power (well 340 PS anyway).
Not in a particular hurry to swap, or displeased with the Z, just aware of its age.