I have no issues owning a car of that mileage but would only wish to buy a car of that mileage if I could be reasonably sure it had led an easy life doing long trips in the hands of a single owner (perhaps two). You can go some way towards verifying this by checking its condition - a looked after BMW that hasn't spent its life crashing around town shouldnt really have any interior wear, it should look pretty immaculate inside. Second way is to check the service book - upwards of 15k between services = long trips, less than 15k = average trips, less than 12k = life in town.