Hi Patrick,

Anyone that imports a car to Ireland from the UK (or anywhere else) is supposed to register it here before selling it on. In fact, there are strict rules about the amount of time they have to do that, so you could be stung with a fine if you buy a UK car that has been in Ireland already for a while. On top of that of course you will be liable for all the import taxes - VRT, NOx levy and potentially VAT and customs duty depending on where the car has come from.

I suggest you encourage the seller to register the car here before you buy it.