I agree with those who say that it's best not to look too far, maybe an online check to see that its still on the road is enough without delving deeper. 7 years ago I bought a fabulous MGRV8, which for those who are not aware was a special edition (1993-1994) of the MGB but with Rover V8 fitted (have a look on line at some pics, stunning to MGB fans). They only built approx. 2000 under the code name project adder and the Japanese market snapped up most of them. They started coming back on the second hand market in the early 2000's, usually with ridiculously low mileages, and I bought one with 11,000 miles on it and in great condition. Mine was very rare as it had factory electric power steering which made such a difference as otherwise it was unacceptably heavy on the steering. How I loved that car! I fitted every known modification and improvement and then enjoyed driving it and taking in that fantastic burble of the V8. To say it was cosseted is an understatement, I bought a Carcoon inflatable, filtered positive pressure, zip up storage bubble for the garage and there the car lived until it came out to drive or for it's regular wash, detail and wax.
After 3 years, not being a wealthy man and also becoming less than enamoured with Rovers decision to build the car with more or less original leaf spring rear suspension (wrong!!) I decided to sell. A husband and wife (lovely people) purchased the car for £1000 more than I originally paid and I felt sure it would be loved.
The following Christmas I received A card from the owner (it was the wife's car) the front of the card had a photo which showed the RV8 outside with about a foot of snow all over it and a note inside saying "thought you might like to see the car again (sorry it lives outside)" No, I did not want to see it again (not in this way) and know that it was now just a car being used in the way that it was built to be used, but not in the way I wanted to remember it. It genuinely hurt, not just me but also my 14 year son who also adored the car. Silly I know, the owner was entitled to use the car in any way she saw fit and was genuinely keeping in touch in a friendly way.
If I ever sell the Z4 (unlikely as it is the only car I have owned, apart from the RV8, that I sometimes have to stop myself from continually taking out of the garage just to have a drive in it) I will never attempt to trace it in later years.