The next-gen RS4 was last spied by a our eagle-eyed sharp shooters at the end of October 2015.
That early engineering mule didn't wear any camouflage and, thanks to its wheel arch extensions, resembled a high performance version of the A4 Allroad.
This prototype wears a layer of black and white disguise below the belt line, suggesting that it's using some production-ready exterior components.
Up front, this RS4 features a unique bumper assembly with a disguised single frame grille and a prominent splitter, as well as gaping air ducts underneath the headlights.
Out the back, there's a subtle rear diffuser element that's bookended by large oval exhaust tips.
Hidden away beneath the camouflage are wheel arch flares that don't quite lune up with the front and rear bumpers. This, along with the roll cage, suggests that the next-gen RS4 is still has a fair bit of development ahead of it before it is showroom ready.
The prototype also features Recaro racing bucket seats for the driver and front passenger, cross-drilled brakes up front, and fat, low profile pieces of rubber wrapped around large alloy wheels.
Rumours suggest that the new RS4 will ditch the 4.2-litre V8 that's been employed during the last two generations. In its place, it's said, will be a 3.0-litre turbocharged V6 with electrically assisted forced induction for improved low-end responsiveness.
Given that the latest-generation S4, with a 260kW/500Nm 3.0-litre turbo V6, and the about-to-be-superceded RS4, powered by a 331kW/430Nm naturally aspirated 4.2-litre V8, have quoted 0-100km/h times of 4.7 seconds, it's reasonable to assume that the new high performance wagon will be faster than both to the metric tonne.