The Audi RS3 was seen testing in S3 duds without any camouflage. This was probably thought to be enough to disguise what it really was but the photographer could tell by the sound as well as some of the features of it. It was spied near to the Nurburgring in testing.
The sound was reportedly like a five-cylinder engine which means that it could have the TT RS engine. This engine is capable of 340 horsepower and is a 2.5 litre with turbocharger. This could be The engine for the A45 AMG from Mercedes-Benz. The test mule here has bug brakes which make it seem like the car will have high performance. The oversized wheels with six piston calipers and Audi RS wave brake rotors certainly prepare it for high power.
It is expected that the production form car will look a lot different though. It is expected that it will look a lot sportier for one thing and there will be a more aggressive look to the front and dual exhaust outlets with two pipes. The S3 may not have arrived in North America yet but now there is excitement around the RS3 too.