The Jazz is a very reliable car.
Most common issues talk about noises from door seals (needing some lubrication), aerodinamic noises and, as I said before, some troubles with clutches and the audio unit but only for early cars. The middle age restyling carried few modifications, just led headlights for the EX, different bumper design and other minor details, the core of the car has been left unchanged.
Feel safe to buy it.