It has the potential to be a consummate all-rounder. The new-found length means six-footers can stretch out in the back, with only minor head room grumbles on account of the sloping roof. The boot is 20 litres more generous than the coupé’s, too, although that’s hardly a deal breaker. 

There’s even a ski hatch, itself more useful than the middle seat it occupies, which is effectively unusable for all but small children on account of the hefty transmission tunnel and climate control panel. Still, there’s a fast 5 and 7 Series if you must frequently carry three in the back. 

The weight and dimensions are important to consider as they make the M8 Gran Coupé a good chunk longer and a fraction wider than the already pretty unwieldy-for-Britain Panamera. Only the aforementioned Mercedes-AMG (I’m not repeating its full name again) is wider.

All three cars definitely seem more at home on wide, well-sighted German or American Tarmac. The M8 in particular suffers from a narrow windscreen field of vision and long bonnet where you cannot make out the extremities of the front-end. At low speeds, you’ll be making prodigious use of its clever virtual-reality parking camera system, with cameras that actually rotate with the steering lock. 

The size remains in the front of your mind when you open up the taps, although you may be distracted by the baffling array of configurable drive settings. There’s the usual three-stage system for the chassis, steering, brakes, all-wheel drive system and engine map, but also a separate switch on the gearshift for change ferocity and two preset buttons on the steering wheel. You can also choose from three modes for the instruments and head-up display. 

Spend time finding the sweet spot (ours was engine in the middle setting, dampers in the softest setting and 4WD into Sport) and you’ll find the M8’s dynamic capability to be very strong. Body control, composure and agility are commendable, and the all-wheel drive system always feels rear-biased. More so when you switch the DSC to fully off and select 2WD mode, where it becomes entertainingly playful in the right scenario. Only the distant feel and odd weighting of the thick-rimmed wheel is a black mark.

We’ve not got many complaints about the way the twin-turbo V8 delivers its performance. With so much of it on offer, you’d need the world’s finest internal accelerometer to detect the Gran Coupé’s extra weight over the two-door version – both claim the same 0-62mph time, for example. It’s not an explosive engine or one bristling with aural character, but it’s mightily effective when called upon and pleasingly docile when not.

Like the two-door M8, then, the Gran Coupé still does an agreeable job of feeling like an oversized sports car. Trouble is, roads where you can uncover its capabilities are infrequent in the UK, so most of your time is spent with disciplined metering out of its considerable performance reserves while you attempt to keep it within the slim boundaries of your lane. There are flashes of brilliance here, but only when you push on.