A total of 34 Northern registered cars were seized by customs officials in Inishowen during a two week period in April, according to provisional Department of Revenue figures secured by the Journal.
This week customs officials accompanied by Gardai once again manned checkpoints close to the border although no figures were available.
A Revenue official confirmed that anyone living in Donegal, even if working in Derry "are not permitted to drive
non-Irish registered cars."
Nationally 3256 cars were challenged by customs officials during that two week blitz and more than 20%, that is 658, were found to be non-compliant.
A spokesperson confirmed: "276 of these were seized for non payment of vehicle registration tax (VRT) and warnings issued for the remaining 382. Seizures were concentrated in border areas as well as in Cork and Dublin.
"The total amount of VRT at risk was €1,404,591.
"To date €351,045 has been paid and penalties of €118,323 collected.
"It should be pointed out that this operation is part of our ongoing enforcement action and not just a 'one off' operation. Revenue will vigorously pursue the non-payment of tax in this area, taking prosecutions were appropriate," warned the official.
Holiday homesThe Journal was contacted by a number of readers with holiday homes in the South who had been stopped at last week's checkpoints however a Revenue spokesperson confirmed: "There is an exemption for temporary importation for holidays, business trips etc."
Asked if those drivers who have a family home in Derry and a work place in the Republic need to have their vehicle re-registered, the answer was: "This would depend on the individual case.
A person working in the Republic on a contract and whose personal ties are in Derry and if they can show that they return there regularly, would not need to register their car in the Republic."
Permanent addressesOn those who have permanent addresses in each jurisdiction: "A decision would need to be made, based on the facts of the case. Generally, a person cannot be resident in two different places.
A number of issues would be taken into account such as where they pay Income tax/claim, for example. In cases of doubt a person is generally deemed to be resident in the place where their personal ties lie, their family/family home etc.
According to the Irish Drivers Association Custom officers are acting outside the law when they confiscate cars by the roadside. Donegal Spokesperson, John Doherty, told the Journal: "If they have a problem with a car owner they should issue them with a court summons which is proper process. Fight it out in front of a judge not by the roadside."