OP, the last one of these which I recall gave a similar account but then the OP PM'd me to give the real story!
If your friend, who was the hotel guest, could contact the hotel and explain something along the lines of them asking to meet you and that they kept you talking then perhaps they might succeed on your behalf, but I wouldn't give much for your chances with a direct approach as you weren't even a hotel guest.
But unless your friend could do this ASP then IMO try and get the discount re-offered yourself and the simplest way is to name the driver if not you. If this isn't an option, then as you're beyond the 28-day period I would not refer to the wording of the PCN. Sorry, but you're trying to get them to re-offer the discount and if they don't and the matter finally went to court then I couldn't see a judge giving this omission the time of day because, read as a whole, passing the PCN to the driver is relevant(as with Notices to Hirer) to inform the driver/hirer that the creditor had taken the preliminary mandatory step of issuing a bona fide PCN. But if you were the driver or you don't seek to pass the buck to the driver then this element of PoFA is academic, in my opinion. It might carry weight with an assessor, but you're not at this stage.
With apologies to views to the contrary, but do you really want to have this hanging over you for up to 6 years gambling that they'll forget when in all probability you'll be the one to forget.
But you're not at this decision point yet.
