This should be the perfect marriage – BMW’s incredibly powerful twin-turbo 3-litre diesel engine and the suave yet practical 6-series coupe. And it does have its appeal: the engine is super-torquey (how does 428lb ft @ 1700rpm sound?) and provides effortless performance, the six-speed automatic gearbox is silky smooth and the interior is beautifully finished. As a place to spend lots of time you can only conclude that the 635d Sport is a mighty impressive car.

There are niggles though, and the more miles you cover the more annoying they become. First there’s the diesel clatter, which is pretty horrendous at cold but never really dies away even at a cruise.