Toyota itself might disagree though, and will display just such a vehicle at the upcoming 2013 Tokyo Motor Show.
It's called the Aqua Air, and as you might know already, Aqua is the name given to the Prius C in its home market of Japan. It's a big seller for Toyota, so spinning models off the platform makes a great deal of sense.
As well as the name, the drivetrain is a dead giveaway of the Aqua Air's more humble beginnings. Under the stubby nose sits a 1.5-liter Atkinson-cycle four-cylinder gasoline engine. That forms part of a gasoline-electric hybrid drivetrain, with a system output of around 100-horsepower--just like the Prius C.
Drive is through Toyota's e-CVT epicyclic transmission, so there's no quick-shifting manual here to enhance the Aqua Air's driving experience. On the plus side, economy is impressive. Toyota claims an optimistic 80 mpg on the Japanese cycle, but given it similarities to the Prius C a real-world 50 mpg looks more likely.
Whatever you think of the render's striking color scheme there's no doubt the Aqua Air looks a little racier than the standard car, with a large front grille and a set of intricate headlamps. It rides on large alloy wheels too, while the interior render shows a cabin near-identical to the Prius C--just a little more vibrant.
It's no out-and-out sports car, but as a gas-sipping alternative to the MINI Cooper convertible, it's actually quite appealing--but whether they'll make it (and bring it to the U.S.) is another matter.
The Aqua air will be joined at Tokyo by two other Aqua concepts. The first is a crossover-style car called the Aqua Cross, comprising chunky body cladding and a set of roof rails. The other is the Aqua G Sports, tuned by Toyota performance partner Gazoo Racing.
Further details are sure to follow from the show itself, so keep your eyes pinned to our full Tokyo Motor Show page.