For buyers, the supermini category has never been more important. Why? Because modern examples of the breed are now for the first time large enough to function as complete family cars. Take, for example, the model we're looking at here, Kia's fourth generation Rio. It's as big as a turn of the century Astra or Focus from the Family Hatchback segment, the next pricier class up. More importantly, it's the first really top class supermini the Korean brand has ever bought us. It's a progression that anyone familiar with Kia will have been expecting. The first two generations of Rio were quite embarrassing but the MK3 model of 2011 was pretty class-competitive. When the wraps came off this fourth generation version in the autumn of 2016 though, it was clear that it was going to be a bit more than that and this design has been further improved in the updated form we look at here. This is a car that targets nothing less than the top of the segment in terms of the things that really matter to supermini buyers - styling, running costs and everyday practicality. How close it gets is what we're here to find out.