It's a hybrid test vehicle with bits borrowed from hotter versions.

The previous-generation BMW X5 skipped the typical mid-cycle facelift and headed straight to the G05 model available today. The fourth iteration of the midsize luxury SUV hit the market about two years ago, and it looks like the Germans are already working on a nip and tuck. Or are they? An interesting prototype was just spotted by our spies based in Bavaria, but we’re not sure this is actually an X5 LCI.

For starters, why would BMW use provisional headlights for only a facelift? In addition, the front doors (and tailgate) have “Hybrid Test Vehicle” stickers, but the front bumper seems to be taken from the X5 M, much like the blue brake calipers. Moving at the back, those exhaust finishers conceal dual tips on each side of the bumper in an arrangement we’ve seen on the X5 M50i.

Gallery: BMW X5 prototype spy photos

The orange side markers suggest this is a prototype for a US-spec X5, while the lack of a license plate indicates the vehicle wasn’t registered. As you can see from some of the attached spy shots, the security staff assisting the truck driver wasn’t exactly happy the test vehicle was being photographed while being unloaded.

The fact it was missing the front radar adds to the confusion, and while interior images are not available, we can see from some angles there was some sort of testing equipment attached to the center console. If by any chance this isn’t an early sighting of the facelifted X5, we could be looking at a test mule for a hybrid powertrain.

That’s not a far-fetched assumption considering electrified performance models are coming, with the crown jewel rumored to be an X8 M with 750 horsepower. It will reportedly pair the ubiquitous twin-turbo 4.4-liter V8 with an electric motor for a plug-in hybrid setup. The aforementioned M50i utilizes this combustion engine, so maybe that’s why this test vehicle had those M Performance bits.

While the jury is still out regarding the identity of this vehicle, we know for a fact the quad-turbodiesel is dead. Not just in the X5, but also in the other models carrying the M50d suffix. BMW previously said the intricate B57S is too expensive to produce and tweak to keep up with stricter emissions regulations. Its last hurrah is in a Final Edition X5 and X7 M50d where the inline-six powerhouse delivers a mountain-moving 700 Newton-meters (516 pound-feet) of torque.