Basically these cars are MoT failure. Japan has a much tougher vehicle inspection regime called the Shaken tests, at three, five and seven years old, then every year. It can cost more to get the car through a Shaken test than it is worth. So, though the cars still run, they are auctioned off for export to poorer countries like the UK. That's what you're buying, plus the considerable cost of transport to the UK, EU import duty of 10 per cent and UK VAT of 20 per cent.