Have a look on some of the police forums, money saving experts forum, and many others including Anne Robinsons consumer show (you tube) all the advice is to throw the first, second, third and so on invoices in the bin as they are unenforceable. The invoice can look similar to an official parking fine but is simply an invoice, just ignore the threatening content. The only parking fines that are enforceable are those issued by the council or the police etc. There is a possibility that the law may and I mean may change in the future where you will, as the owner, be legally required to supply the drivers details but this has not been introduced yet. Also remember they have to PROVE who was driving the car so you as the owner could have lent your car or even taken it in for repair and it was out on road test when the invoice stuck on your screen was issued.
