The new Mercedes-Benz C-class has got its first official unveil in sedan form at the Detroit motor show 2014.

The Mercedes-Benz C-class line-up will grow to include models without a direct predecessor, according to Daimler chief Dieter Zetsche. Among those tipped to join the line-up are a cabriolet version and a sport coupé to rival the India-bound BMW 3-series GT.

According to Zetsche, the Mercedes A-class line-up now has the CLA and the GLA, the C-class line-up will also have more models.

The new C-class is the first Mercedes to be spun off the firm’s modular new rear-drive MRA platform, an architecture that allows greater freedom of body styles.

“You have freedom in the platform with proportions and dimensions,” design chief Gorden Wagener told Autocar UK, “so you can create some pretty diverse cars from that.”

Designing the first model off the platform was a particular challenge, according to Wagener, as you’re “not just defining a car, but 10, 15, 20 other cars – so you can’t mess it up”.

“A three-box saloon is also the toughest style of all to design,” he added. “A sports car is hard to get wrong, but you have to work on proportions a lot with saloons.”

Common design traits of the C-class family will be the long-bonnet, cab backwards profile to emphasise it as rear-wheel drive, as well as the dropping line from the bonnet to help lengthen the bonnet and make the car’s weight sit over the rear wheels.