Four-up drag racing? High-speed passenger rides around the Nordschleife? Otherwise I’m afraid I don’t really know what the BMW M5 CS is for. Here’s a saloon car that weighs two tonnes with a driver and some fuel on board, has more power than any other BMW M-car, is much more demanding in normal use than the far cheaper M5 Competition and that has two individual bucket seats in the rear rather than a more useful three-person bench.