Just in from our spy photographers from the coldest areas of Sweden are shots of a very interesting black A6-based Avant. With a more aggressive front fascia (spotted on some earlier test mules), a wider track and add-on fender flares, there's no doubt that this is a preproduction prototype of the RS6 Avant. There're also ceramic brakes underneath those A8 wheels which only seem to further confirm the car's RS status. It is expected that the RS6 will use the same 4.0 TFSI bi-turbo V8 as the S6, S8 and even the new Bentley Continental GT V8.

Final power levels remain to be seen, but iterations of the 4.0 TFSI in the S8 and the Bentley are over 500hp. Paired with that wider track and those aggressive brakes should make for an impressive configuration. On the outside, while the front chin spoiler you see here may be close to production, other changes will also likely take place. The lower intakes may or may not change shape just a bit and most certainly the add-on flares will give way to integrated fender flares and possibly box flares like those of the C6 RS6 that harkened back to the Ur-Quattro from the 1980s.

We also wouldn't be surprised to see the next RS6 drop further weight through the use of lightweight Carbon Fiber Reinforced Plastic (CFRP) on elements like the front fenders as we've already seen on the RS3.