Why is the Audi A2 considered one of the most innovative cars of its time?

I am interested in learning about the unique features and design of the Audi A2 that made it such a revolutionary car during its release in 1999.

The Audi A2 was a pioneer in lightweight construction, making use of aluminium in its body, resulting in improved fuel efficiency and overall performance.

The A2 also featured an innovative aerodynamic design, with a drag coefficient of just 0.28, making it one of the most streamlined cars of its time.

The A2 was ahead of its time in terms of technology, with features such as a wireless car phone, voice control system, and a keyless entry system.