The Audi bird is a perfect metaphor for the new Audi A6 Avant’s ultra-lightweight construction, offering drivers a more agile and efficient performance. Flying nimbly through a surreal landscape populated with trees, flowers and fauna made from petrol pumps, road signs and traffic cones, the metal-framed bird boasts design elements that echo the A6 Avant — right down to its breast, which replicates the distinctive Audi grille. The hummingbird…