First, you'll need a large and punchy engine. If it has to be a diesel, and I accept there are circumstances where this is a more logical option for some people, then a 308hp 3.0-litre six should do it. Second, it should be automatic, of course, and, as we're not What Car? here, it should drive through the rear wheels only. Third, it should see off 0 to 62mph in around 5 seconds, waft up to a limited 155mph with ease, return 50mpg, seat four comfortably and preferably have four doors. It should also be as luxurious as humanly possible and, because it's a BMW, it must grip and handle like the very best of sporting saloons.
Not only does it satisfy all of the criteria I outlined at the beginning, the Gran Coupe also has the finest and most consistent shut lines and panel gaps of any car I've studied recently, including other BMWs. That only adds, even if subconsciously, to the impression of quality this big Beemer gives off, heightened in the car we've found by its metallic Carbon Black paintwork.
At £22,480, though, it makes real sense. It's a great cruiser, a nimble sportscar, a refined and luxurious gentleman's carriage and a classy grand tourer, and it's barely run in.
SPECIFICATION - BMW 640D GRAN COUPE
Engine: 2,993cc, 6-cylinder turbodiesel
Transmission: 8-speed automatic, rear-wheel drive
Power (hp): 309bhp@4,400rpm
Torque (lb ft): 464@1,500rpm
First registered: 2013
Recorded mileage: 45,000miles
Price new: £63,900
Yours for: £22,480
See the original advert here