The strongest arguments would be;
1. The NtK does not contain the statutory wording required by POFA Schedule 4 Paragraph 9(2)(b) so liability cannot be transferred from the unknown driver to the keeper - marginal argument.
2. That the notice relies on a 'time on site' argument and does not show or prove any 'period of parking' - this is the stronger argument - that the Defendant could reasonable say, "That is took the vehicle driver around 10 minutes to locate the exact address and that no parking actually occurred before that point in time - it also took a few minutes to leave the site after the parking event - with all this considered the actually period of parking was within the terms of the alleged contract."