I suggest some fixes & imrovements

[QuietNoise]

Registration plate:
Line 417:
$regex = '/^(\d{2,3})[\ -]([A-Z][A-Z]?)[\ -]\d{1,6}$/';
The regex should allow for reg without spaces / special characters. I.e. make them optional
$regex = '/^(\d{2,3})[\ -]?([A-Z][A-Z]?)[\ -]?\d{1,6}$/';

Line 448:
if (!Validate_IE::yearBetween87and12($year)) {
Function continues to check years for 2 digit plates rather than 3 digit ones (which should be just greater that year 12. I reckon the line could just be:

if ($year < 13) {
	return false;
}