Mercedes-Benz has released a teaser of the IAA concept that is set to be unveiled at the Frankfurt motor show next week. The company has confirmed that IAA stands for Intelligent Aerodynamic Automobile and describes it as "two cars in one: an aerodynamics world champion and a four-door coupé embodying irresistible design." 

 

Although the teaser doesn't reveal too many details, you can see it takes a conventional shape, but gets a double bubble roofline that leads to a sloping hatch similar to the Audi A7 Sportback. The words ‘CONCEPT IAA’ are placed below what looks like a light bar. This design language is likely to be carried forward in next-generation Mercedes models.