Audi is developing a high-performance RS5 sedan variant to join the A5 and S5 lineup soon. The new RS5 may feature a twin-turbo V6 engine and potential plug-in hybrid technology. Audi's RS models continue the brand's history of setting benchmarks in the high-performance luxury car market.

Watch: Can The Audi RS5 Avant Snatch BMW M3 Touring’s Nurburgring Record? A heavily-camouflaged prototype of the RS5 Sedan was spotted during hot-weather testing in Europe, and

Like the Audi RS5 Avant wagon, the sedan gets hugely pushed out wheel arches at the front and the back. They hide the massive tires the RS5 needs to reign in all of its horsepower

Over the last few months, the Audi RS5 Avant has been spotted undergoing testing as it prepares to take over from the RS4, which will become an all-electric vehicle. Since the RS4 was available as both a sedan (once upon a time) and a station wagon,