With Mercedes having just renewed the C-Class and the BMW 3-Series F30 being on the market for only two and-a-half years, Audi’s A4 is the oldest of the German compact exec sedans.

But there’s a new A4 coming and we caught Audi’s engineers testing an early stage development prototype, which was wearing the current vehicle’s body and interior.

The mule is likely used to evaluate the new car’s second-generation MLB platform, which will bring weight savings, despite an increase in width and length for better passenger space.

Powertrains will include newer or improved versions of familiar engines such as the 2.0 TFSI as well as fresh offerings, including the first ever plug-in hybrid unit for the A4 series, which will likely be based on the electrified 2.0-liter TFSI petrol found in the A8 Hybrid.

We’ll have to wait for actual prototypes of the next A4 to get a sense of Audi’s design direction, but we expect a more sculpted body and a cleaner looking interior featuring all the latest tech. Whether that will include Audi’s new fully digital instrument panel that incorporates the navigation system (standard or optional), remains to be seen.

The new A4 in sedan form should debut in the second half of 2015, followed later on by the Avant (station wagon) editions, and the performance variants.

Photo Credits: CarPix for CarScoops

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