There is a public notice on TRA on how they are going to determine year of manufacturing of imported used vehicles. TRA has recommended websites for prospective importers as credible way of determining year of manufacture of a car for tax purposes. TRA has decided to move away from their old era of relying on year prints in seat belts, importation documentation etc. For Japanese cars the recommended site is auction.jimex.co.jp for UK cars ts-export.com and dvla.com for worldwide cars. Source todays papers.