I am not aware of any evidence of the practice referred to.
Imported used vehicles in the categories which are liable to compulsory roadworthiness testing in this country must be tested and passed as roadworthy by a vehicle testing station here before being licensed by the local motor tax office. The categories in question are heavy goods vehicles/trailers, buses, and ambulances over one year old. Taxis and hackneys are roadworthiness tested by the Garda Síochána (public service vehicle inspectors) prior to being licensed.
The Road Traffic (Control of Supply of Vehicles) Regulations, 1991, impose a duty on commercial suppliers of all new or used motor vehicles to supply vehicles which comply with road traffic regulations on the safe construction, equipment and lighting of vehicles. "Commercial suppliers" would include importers, distributors and motor dealers. Any specific allegations that unroadworthy vehicles are being imported, together with supporting evidence, should be addressed to the Garda Síochána who are responsible for enforcement of the regulations.