Well thought I had found one, 57 plate 3.0dSE with 89000 on the clock bit high at £17000. Had a read of the paperwork and MOT's etc and some where missing, but you know when you get the feeling something isn't right, so walked away.
Perhaps I'm being a bit anal as my E93 is up to date with ...

Thanks for the detailed response, lots to consider. I am in the fortunate position to spend a bit more but having thrown many £1000's at BMW dealers over the last ten years I guess I am now trying to be a bit clever and find the holy grail car.

As an avid BMW owner, I am looking to change from my e93 to something more practical and have decided on an X5.
At the moment there seems to be a number of 5-6 yr old high mileage 3.0 diesels for sale at around £16000 which would interest me. Now I know it's a bit of a broad question but am looking ...