Why does the Audi A5 have such a low drag coefficient?

I've heard that the Audi A5 has an exceptionally low drag coefficient of 0.25. Can anyone explain the engineering behind this feat of aerodynamics?

The Audi A5's low drag coefficient is achieved through a combination of its streamlined body design and advanced materials, allowing for improved fuel efficiency and performance.

Audi's use of virtual wind tunnels and computer simulations during the design process has allowed for precise shaping and smoothing of the A5's exterior, resulting in its impressively low drag coefficient.