I fear Tonga has been misinformed, and should check the facts before making a big mistake, and misinform other people.
A non-resident of ireland can buy a car in ireland, and not pay a penny in VRT or VAT, so long as they leave with the car immediatley. Brits were buying their cars here & paying their taxes in the UK, therefore getting cheaper cars. This was due to irish car prices being subsidised by the manufacturers because of high irish taxes (to stimulate sales). We can also do the same ie. go to another EU country, buy a car there not paying VRT or VAT, but you will pay a higher price for that car than irish dealers get them for (ex.VRT, VAT). You would then have to pay the FULL VRT & VAT on landing the car in ireland. So no you will not save money doing this, in fact you might loose money. Now if the car was six months old, you would not have to pay VAT, so it could be worth it then, but then who buys a RHD in Belgium. With the new market rules, the net price difference may not be so big, but irish cars sometimes have a lower spec than their european equilivent.
If you really could save 25% doing what tonga described, dont you think everyone would be doing it? I would like if Tonga can prove me wrong though...