If saloons are an endangered species, estates are critically endangered. That alone makes the forthcoming BMW M5 Touring a special machine, but if reports about the powertrain are accurate, it will be a critically endangered powerhouse that hunts and kills supercars.

We have a new set of spy photos of this beast in action at the Nurburgring. At a glance, it looks much like our first M5 Touring sighting from the end of July, but an extremely close look suggests this BMW is closer to production. The taillights (what we see through the camo, anyway) look different, and the M5's signature quad exhaust outlets are different as well. These pipes appear slightly larger, and judging by the way the car is leaning through the corners, we suspect they are getting a very thorough exercise.

Gallery: BMW M5 Touring New Spy Photos

For that matter, the entire car is getting a hard workout. We're treated to several views of the estate at various parts of the famous track, and through them all the M5 looks supremely planted. Partial credit goes to the wide tyres stuffed beneath flared wings/fenders. We can tell they're Michelin Pilot Sports due to the chequered pattern on the sidewall, but sadly, the car is moving too fast to see a specific size. BMW's xDrive AWD system is certainly helping as well.

Something we can see very clearly are the words electrified vehicle on the door. That confirms the next M5 – both in saloon and long roof format – will be a hybrid. Moreover, it will almost certainly be a plug-in hybrid, taking cues from the XM by fusing BMW's twin-turbocharged 4.4-litre V8 with an electric motor. In the beefy SUV, this setup delivers up to 735 bhp and we're hearing the M5 could get upwards of 750 ponies. Even if things are dialled down a notch for the M5, it will be significantly more powerful than the previous model.

The new 5 Series has already debuted, but things take a bit longer in the world of M. Our sources believe an official reveal won't happen until 2024.