do not be concerned. Like first cars for USA gone long before problems occur.
problems with Serbian workers on 500L car was just few scratches on doors, newspaper and reporters had to add something to make news more juicy.
those workers are some old "workers" who liked pass time, when they got paycheck but didn't work anything, now when Fiat came they force to work and earn your money they want to show how low money they get for work.
Trust me all in Serbia do not support that action, if they think that paycheck is small let go and find other job and let people who want to work.
I just got 500L 7 days ago and I love it.
(sorry for bad english)