John, did you get this sorted?
I was going to suggest checking out the MINI forums. A lot of MINI customers repeat purchase. People usually get a trade in price and the list on the forum in the small window before the collection, for a little higher than the trade in price. (Usually well below trade price) Also active forum members tend to look after things well, and you can review the cars history in some cases through the threads they posted.
A little background is better than none.
MINI can also key read a car and print out its service history on request.
I would suggest totalMini if its for the wife as minitorque is more modified end of things. That said check them all as you never know what might crop up.