To say it's been a long time since BMW built a bespoke M model would be an understatement. In fact, there hasn't been one since the original M car, the BMW M1, arrived on the market in 1978. Every M car since the M1 was based on an existing BMW model. BMW has hinted at bringing back a mid-engine supercar with concepts like the M1 Homage and M Vision Next, but none has reached fruition.

That leads us to a curious trademark from BMW for the name "XM." The filing dates back to October 2020 with the US patent office but was more recently submitted to the UK office on April 5, 2021. Based on existing BMW nomenclature, it sounds like this could be a bespoke, M-branded SUV.

In interviews dating back to 2019, M CEO Markus Flasch hinted that BMW was investigating segments where a standalone M model might fit in. Flasch said such a model would need to have a "combination of precision, agility, and luxury," and he hinted that BMW considered multiple body styles and powertrains. We think a dedicated M SUV might fit the bill here, as evidenced by spy shots showing an all-new upcoming model.

Our spy photographers previously pegged this prototype as a test mule for the upcoming X8 M, but perhaps BMW will use the name XM instead. Whatever nameplate it wears, the car is known internally as Project Rockstar, and it's rumored to pack a hybrid drivetrain combined with the 4.4-liter twin-turbo V8 from the X6 M, producing 750 horsepower. This would be the most powerful BMW model by a wide margin.

It's not the M1 spiritual successor we hoped for, but a new BMW M super-SUV still sounds pretty cool. The car could still end up being called X8 M, but we think it's time for BMW to introduce a bespoke M product. Of the big three German automakers, BMW is currently the only one without a standalone product from its performance brand; Audi has the R8 while Mercedes-AMG has the GT sports car and GT 4-Door.

Before we get too excited about the BMW XM, we have to throw out one more possibility. BMW announced last year, around the same time as the first XM filing, that SiriusXM radio with the 360L platform would be standard on all 2021 models. It's possible that this trademark could relate to this rather than a new model, but we'd prefer to believe that BMW M is ready to unleash something special.