Yes I have also noticed the same, the Doors seems to be having Open/Close sound very different from Any other Car available in Pakistan, to me they sound like closing doors of a Truck,,,,
Seriously.......... may be they are Heavier than the Normal doors and as they claim that the Doors are equipped with Door Beams which most of the Locally manufactured cars don't have. So thats seems a Positive thing to me.... Hope it will prove to be Positive too........