Technically no duties should have to be paid. This a breach of EU rules.
You are quite correct in saying that if the car is over 6 months old or done more than 6000 km then NO import duties or taxes should have to be paid except local road taxes.
As far as i am aware the EU have already written to the Cypriot authorities on this and many other breaches of EU legislation at last count it was 28 letter have already been sent. The ROC government are in the process of changing there own laws which allow EU directives to superseed that of there own. Eventually anyone will be able to import a car from example the UK and not have to pay any duties as long as the vehicle is more than 6 months old, done more than 6000 KM and the taxes have been paid in another EU state. Usually the original registration document from the member state should suffice as proof that taxation has been paid.
There have been many complaints made to Brussels about the non implentation of EU rules in particular tothe importation of motor vehicles.