Dave, its now on 116k
140k is nothing as long as its been serviced properly. The main things that need doing are the oil/fliter changes and change of coolant. Also check the tcs's and shackles for clonking, wondering steering and slight vibrations and listen out for timing chains as well. Apart from that just check the usual things like the cat and that everything works like it should, etc, etc ....
Also check this website out as its pretty usefull:
http://www.honestjohn.co.uk/index.ph...ycar/index.htm
If you have the reg number then give BMW GB a call at the Bracknell office as they'll only too willingly give you any info and servicing history that they have
hth's