fuw,
Regarding your question I would like to share my experience,
A few months back I bought a car, when I went maroor to get it registered I was asked by the lady on the desk to submit Qr-3000/- as a fine for driving a vehicle on the wrong side of the road...

But I was dead sure...it was never happened, so, I went to the main traffic department Madina Khalifa for the evidence & Alhamdolilah! They said sorry it was all by mistake:)