The third-generation Audi TT was revealed last March at Geneva and is abundantly clear that its redesign was more evolutionary than revolutionary. TT loyalists were likely happy about this but from what we overheard at the show many others were hoping Audi would have taken a more dramatic approach. Perhaps that's not too late because the best TT in the lineup is yet to come: the next TT RS. Our spy photographers just snapped images of a new TT RS test mule and we're still left with one question:

What's under the hood? Our sources tell us there are two possibilities: the 2.5-liter five-cylinder found in the RS3 with nearly 400 hp, or a version of the turbocharged 2.0-liter four that'll power the also upcoming Golf R400? Whatever it is, Audi is once again making giving it some extra exterior muscle, such as the two big oval exhaust tips and bigger brakes with drilled rotors. Expect a full reveal this September at Frankfurt.