[vnabhi]

I'm owning a petrol Fiesta, but have never faced any rattling issues. My pals have diesel Fiestas, and they too are rattle free for the past one and half years.
As regards choosing between Verna and Fiesta, it is your call. But I've read that the diesel Fiesta has better low-end grunt than the Verna in city traffic. The Verna's turbo clicks in at higher rpm, and from that rpm level, it is much faster than a Fiesta.
But in day to day commute in thick traffic, Fiesta holds sway, and it is only on highways does it lose out to the Verna.
I've also read that Verna's headlights are very poor and need changing. High speed stablility issues have been reported about Verna on this forum. Many Verna owners have had problems with their left rear door too. Not sure if these have been rectified.
So to conclude, if you drive on highways more, then go for the rocket--Verna. But do check if Hyundai has done something to improve its handling at high speeds.
That is my two cents for you.