Correction: this car was designed under the G21 project for Global 21st Century not a one car design project. The vision was about energy and environment. The mission was to double the mileage of a concept in R&D. The manager in charge of the 1,000 engineers demanded doubling the mileage so the team had to throw out 80 designs to get to the funky little remainder car that became the Prius.
It was designed to get twice the mileage of a standard Toyota compact to unveil right around the Kyoto Protocol. It was being driven as a visionary concept, not as a city car. It became that type of car after the popularity exceeded everyone’s expectations in response to celebrities and more powerful and roomier American versions were exported to Los Angeles.
Did you know that Japanese version has an electric only switch? I imagine it would create lawsuits in the US from abusive users that could burn up the Hybrid Synergy Drive 650 patents, so they left a blank spot on the American dash. The Prius design was driven by an open ended simple goal, double the kilometers per liter.