In order to grab Audi by the rings, BMW is expanding the number of variants for its already popular models, including the recently launched 3-Series. The newly minted sedan is getting its very own coupe version, but rumor has it that this new model will be dubbed the 4-Series and was recently captured by our spy photographers.There’s not much to know about the 4-Series just yet, but it looks as though it will be a smaller version of the 6-Series with a design language inspired by the 3-Series with a sportier character. The vehicle will be a few inches longer than the sedan version and will feature a more aggressive front end with the new-style exposed, three-dimensional BMW double kidney grille and a larger rear window.Under the hood, BMW will place a choice of four engines - two petrol and two diesel - including the new 245bhp 2.0-liter four-cylinder petrol and the more powerful 435i engine with an output of 306 HP. As with all the other BMW models, all-wheel-drive xDrive versions will be available as well.When the new BMW 4-Series goes on sale in 2013, it will be looking to take over the Audi A5 Sportback’s piece of the market.