Despite America’s reluctance to embrace compact econo-cars, Mercedes’ diminutive Smart Fortwo is selling far beyond expectations in the few months that it’s been on sale in the world’s biggest car market. Sales of the car were expected to be strong in urban areas like Los Angeles and New York but the car is also proving popular in Middle America.

Customers are also choosing to equip the cars with many of the optional extras. Speaking with Automotive News, the CEO of Smart’s official U.S. importer, Roger Penske, revealed that customers are spending on average $1,600 on extras – about 15% of the car’s base price.

"This is not a customer who is buying a car because it is cheap," Penske said. "People are interested in its urban friendliness and its fuel economy," he said. "It is the total of what we offer."

Coinciding with the car’s launch in the U.S., officials took the car on a 50-city road trip to promote it at sporting events and retail outlets. The tactic proved so successful that the cars are now sold out for the next two years.