I am informed by the Revenue Commissioners that section 132(3)(e) of the Finance Act 1992 provides for the charging of a "nil" rate of Vehicle Registration Tax (VRT) on categories of motor vehicle that are designed and constructed in a manner specific to their purpose and that are used for public services such as road cleaning, road construction and for the exclusive transport of life boats and their gear or any equipment for affording assistance in the preservation of life in cases of shipwreck or distress at sea.
Apart from these exemptions, there is no provision for relief from VRT for vehicles used in emergency services; vehicles are taxed on the basis of 'type' rather than 'use'. Accordingly, commercial vehicles used in mountain rescue services, including vehicles for the carriage of goods and vehicles for the carriage of 10 or more persons, are liable to a flat VRT rate of €200. Other vehicles are liable to higher VRT rates depending on the specifications of the vehicles in question.
Further information can be accessed on the Revenue website at the following link:
http://www.revenue.ie/en/tax/vrt/vrt-guide.html#section12