The BMW X8. It isn’t officially confirmed, but rumours and reports suggest it's all but inevitable. Slotting above the X7, it would be a rounded-roof crossover in the same vein as the X6 is to the X5. It could also be supremely powerful with full M treatment, and that’s the subject of a new – and also decidedly unconfirmed – report from Car magazine.

How much power are we talking? The report claims an X8 M will boast a hybrid powertrain combining BMW’s familiar twin-turbocharged 4.4-litre V8 with an electric motor adding upwards of 200 bhp (149 kilowatts) to the mix. The end result is said to be a 750-bhp (559-kW) all-wheel-drive monster that has rear-wheel-drive bias and can send all power rearward, similar to the current BMW M5. The report further claims this mental X8 M has a codename Rockstar, and if drivers decide to funnel such power to a pair of wheels on a big crossover with presumably no driver assists, it will take rockstar skills to keep it under control.

However, take everything here with a grain of salt. Aside from being unconfirmed, and Car makes absolutely no reference to where this information comes from. Is it found through leaked documents? Is there an insider source? We don’t know and BMW isn’t talking, but having an insane level of power is certainly familiar territory for M-badged Bimmers. Furthermore, with no official M version of the X7 planned for production, going absolutely ballistic with what would be BMW’s new flagship certainly seems appropriate.

Of course, before a crazy 750-bhp X8 M can destroy tyres, a standard-issue X8 needs to arrive. Previous rumours said either a concept or full production vehicle might debut by the end of 2020, but we haven’t even seen a camouflaged prototype yet. As such, we could be at least a couple of years away from the entry-level X8, never mind an M model. That’s a lot of time for ideas and rockstar ambitions to both evolve, and fade away.