14 days only applies to private cars registered in your name. If it's a company car, lease, hire etc, the rules are different. Pepipoo is a good resource. Chances are, they will still chase you & send all the threatening letters warning of dire consequences if you dont cough up. Notwithstanding the time delay, you must still fill in & return the NIP, as not doing so is an additional offence. You can of course tell them that you geniunely can't remember who was driving as it is so long ago, that's assuming that there is more than 1 driver on the insurance. You might still end up in court, but you will most likely win. It's the size of your cojones that decide than one.
Rule#2: Never argue with an idiot. He'll drag you down to his level & then beat you with experience.
Rule#3: Tha' can't educate pork.
Rule#4: See rule#5