Ever since the Audi A3 sedan concept was first unveiled in 2011 at Geneva, we've been hoping to hear more news about a potential RS3 Sedan. Although both the production A3 and S3 Sedans were revealed at the Shanghai Motor Show back in March, word is coming in that Audi is already at work planning the more extreme high-performance RS3 Sedan. While Audi hasn't officially confirmed the rumor just yet, the reason is clearly there to build it and it's called the Mercedes-Benz CLA45 AMG.

The S3 Sedan's 2.0-liter TFSI will be good for around 300 horsepower, but that output won't be enough if Audi is serious about taking on AMG's latest. To counter that threat, Audi would likely drop in the 2.5-liter turbocharged five-cylinder with around 340 horsepower that also powers the RS3 Sportback and TT RS. For comparison, the CLA45 AMG packs a turbo four that produces 355 horsepower and is mated to a seven-speed dual-clutch that sends power to all four wheels. We're assuming an RS3 Sedan would come with the automaker's Quattro all-wheel-drive system so, on paper at least, both cars would be formidable competitors.