Growing up in 1960s Austria, Erwin Wurm and his friends had an expression for expensive automobiles that were instantly recognizable and driven, they surmised, by rich people: “fat cars.” As one of contemporary art’s more iconoclastic conceptual artists, the Vienna-based Wurm has spun the term into a series of corpulent, life-size sculptures that contemplate our consumer society.

“The car and the house, the two objects which I’ve made fat, were always the most beloved objects of human beings—before they created the iPhone,” Wurm says with a chuckle. “It’s how we address our well-being, our wealth, our coolness. It’s social status.”

Wurm has fattened up Porsches and Ferraris, but his latest is a lumpy, forest-green Mini Cooper, which is on view in a solo exhibition at London’s Galerie Thaddaeus Ropac through March 23. The oxymoronic Fat Mini takes a humbler vehicle as its subject but still explores the biological, cultural, and artistic associations with weight gain that have long intrigued him: At the most basic level, he notes, sculpture is about adding or subtracting volume. (Last summer in Brooklyn, in conjunction with the Public Art Fund, his bulbous, yellow Hot Dog Bus handed out some 50,000 free wieners; the people who ate them, Wurm posits, could be considered sculptures themselves.)