No other car has a heritage quite like G178 SGO, a 1990 BMW 325iS automatic built for the North American market. Happenstance dictated that it ended up as part of Mobil's research and development fleet, whereupon it spent four years on a rolling road, running around the clock at 45 to 85mph and pausing only for routine maintenance and synthetic oil changes every 6,000 miles.
We sometimes hear of antique cars that have covered 450,000 miles on their speedometer representing some kind of durability record, but this BMW was retained in captivity until it had been around the clock 10 times. It is a genuine 1,039,491-mile car, although the first million were covered in laboratory conditions.
Once its task was fulfilled, the car was stripped down (engine wear was found to be relatively light) before being reassembled and dispatched to work as a promotional vehicle in the US and Europe. Its recent history is a little blurred, but a trip to the scrapyard seemed imminent until Mobil rediscovered the car in Edinburgh, where it had spent a few years on a dealership forecourt. It has since been recommissioned and returned to active service… albeit in a real world contaminated by speed cushions.