It's been only a few months, and already the Toyota Prius C's production is unable to meet demand around the world. When the car went on sale, it was reported that Toyota received 120,000 orders within the first 5 days.
As a response to the shortage, Toyota is stepping up production of their Prius C in their Kanto Auto Works plant (the only place in the world where the Prius C is made) from 20,000 units a month to 30,000 units. This would bring up the annual total to 360,000 cars from an initial plan of 240,000.
The Kanto Auto Works Plant assembles the Prius C for all markets. With such high demand in the U.S., Japan (where it is known as the Acqua) and elsewhere for the entry level hybrid, a 50% increase in production capacity will hopefully address the supply shortage.