Taxis in Belfast - nice cars!

[MitchT]

Just returned from a long weekend in Belfast. Been a few times over the last five years or so. Each time I've noticed that many of the taxis are immaculate, nearly new, high end saloon cars such as a 5 Series, A6, E Class. This morning's transport to Belfast City Airport was a Mercedes S500! How is it possible for such expensive cars to be used as taxis when back in my native Yorkshire you're lucky to get anything more than a leggy Toyota Avensis? Are there some amazing lease deals in Northern Ireland?