How does the Audi A2 achieve its low drag coefficient of 0.25?

I've read that the Audi A2 is one of the most aerodynamic cars of its time, but I'm curious as to how it manages to achieve such a low drag coefficient. Can you explain the specific design features that contribute to its efficiency?

The Audi A2's streamlined shape, with a long and flat underbody, helps reduce drag by minimizing air resistance. Additionally, the side mirrors are designed to redirect air flow away from the car, further reducing drag.

The A2's lightweight aluminum construction also plays a crucial role in its aerodynamics by reducing overall weight and improving handling. Furthermore, the smooth surface of the car's body also contributes to its low drag coefficient.

Audi's use of computer simulations and wind tunnel tests during the car's design process allowed for fine-tuning of the body shape and contouring to optimize aerodynamics and achieve a lower drag coefficient.