Hi Dave,

If you already own the car in London, and have done so for more than six months, with documented proof of that, and you want to bring the car to Ireland to register in your name, then there should be effectively no taxes.

However, assuming that is not the case, you will be liable for VRT, a NOx levy, import duty and VAT. 

That 158g/km emissions value gets uplifted to 180g/km for the purposes of calculations, making it equivalent to WLTP. That means 31 per cent VRT. What is that 31 per cent of? The Open Market Selling Price (OMSP) as Revenue determines it, i.e. what it thinks the car is worth on the Irish market. That will be altered by options fitted and mileage, etc. so your guess is as good as ours, as you know your car. 

The import duty is 10 per cent of the price of the actual car landed here, including transportation. 

Then there's 23 per cent VAT.