Hyundai i30
Hateful, gutless, insipid little units with the turning circle of a river barge. Fine if you're over 60 and are buying one little car to last you until you die, but for anyone who needs a car for practical reasons, stay the hell away. Especially considering you can get excellent bargains on last-model (pre-facelift) Skoda Octavias this year with better equipment for less money.
Similarly, avoid the feeble Chevrolet Spark and plasticky Dacia. From the original list, only the Fiat Panda and Suzuki Alto are viable options on the sub-30k market, but it all really depends what you're planning to do with the car. I get asked for new car recommendations all the time "just for something small to get to work and do the shopping in", and the current market of small hatchbacks are equally fine for that sort of thing. It's when the buyer adds "and the occasional drive to Croatia" that changes everything, and that's where you need the 50k zl+ models.
But I still think buying a brand new car is a waste of money.