What's all this about?

BMW is going to enlarge its X family and, having already shown us the forthcoming X2, all the numbers up to six are therefore already taken. So, in the words of Yazz and the Plastic Population, the only way is up. Therefore, say hello to the BMW Concept X7 iPerformance. Because you can hardly miss this hulking great monolith.

So you don't like the styling, then?

It's not that we don't like it, more that... it's quite a bit to take in. Despite all the protestations that would likely issue forth from chief designer Adrian van Hooydonk if you were to say as much to him, the X7 looks broadly like what you'd imagine it to be: a stretched X5. OK, we can draw attention to the ma-HOO-sive front kidney grilles, or those squinty headlights, or the big front intakes with the vertical lines next to them, or any other number of creases and sweeps of designer's pen that are supposed to shout 'ULTIMATE LUXURY MACHINE', but the fact is this is close to a production reality, so it's basically a very big, browny-bronze X5.

Close to production? How close?

BMW says we'll have the production X7 in 2018, so we're guessing this is 'concept' in name only, being rather more of a prototype. Fans of BMW's oft-times arcane internal nomenclature/sub-brands might have spotted the 'iPerformance' bit of the name and realised this is a plug-in hybrid. Well, bravo you sleuths, because that's exactly what it is. Electric motive power teams with a BMW TwinPower Turbo petrol engine and we'd be very surprised if this was a million miles removed from the 2.0-litre electrified drivetrain of the X5 PHEV.

Is this going to be a seven-seat SUV?

It is indeed. BMW already offers as much as an option on the X5, but in that instance the rear-most two chairs are rather intimate. The Concept X7 is actually a six-seater, so that it can have fancy captain's chairs mounted on slender rods to maximise foot-room, but you can bet your bottom dollar that this will be BMW's retort to the Mercedes-Benz GLS, a model for which BMW doesn't (at the moment) have an analogue.

And that interior?

Concept-esque, but the 12.3-inch instrument cluster is worth noting, as BMW is a little bit behind both Mercedes and Audi when it comes to showy TFT driver displays and this looks like it will bring the marque to the forefront of the digital battle. Meanwhile, there are plenty of screens dotted around for the full connectivity experience, swathes of high-end leather and open-pore ash wood trim and a big panoramic roof up top to flood the cabin with light.

What else can you add?

Well, the concept is finished in Manhattan metallic paint and sits on almighty 23-inch alloys, if you're interested. Perhaps more intriguing is the coterie of Beemers the X7 will join - along with the 7 Series, revived 8 Series, i8 PHEV and the forthcoming i8 Roadster, these five model lines will make up BMW's high-end luxury offering. They will all wear a new type of roundel, as well, which is black and white, rather than blue and white, and which has the full brand name of 'Bayerische Motoren Werke' transcribed in full. BMW used a similar design of badge precisely 100 years ago.