All I know about mine is that it used to reside in Beaconsfield. When I got the car there were still addresses saved in the satnav, but I didn't keep them. Never thought to Google map them to hunt for the Z4. I emailed the dealer who was stamped in the owners manual just to see if they had any kind of service history available but they said they destroyed all records when the Z4 was sold. Sounds a bit strange, I would have thought they'd keep any records for a while in case someone brought the car back to them for work.
I know the Americans have a 'carfax' registry that you can search for information on the car's history - is there anything similar in the UK, or do you rely on the previous owner to provide any service history?