Firstly it is important to note tht in such cases that unless the carpark is council/Govt operated then THIS IS NOT A FINE!
It is a penalty notice and it means the driver of your car breached the terms of a civil contract entered into when he/she parked. The parking company, if it is a legitimate company, will get the registered keeper info from the DVLA and will start to churn out a series of preprinted letters of increasing menace. This frightens many people into paying up.
If they want to take the matter to court (and they almost virtually never do) they need to know who the driver was (as opposed to registered keeper) as the driver is the one who breached the contract. Legally you, as the RK, are under NO legal obligation to tell them. Thus they are f**ked!!
I would do two things:
1. Do not respond or reply to ANY communication from them WHATSOEVER until they actually file a case at the small claims court (which they won't, and anyway if they do, let me know as I have a draft letter that will f**k them right up).
2. Have a look around on Pepipoo forums, here's a good place to start...
http://forums.pepipoo.com/index.php?s=51d28ce600ce2d1d3a561f73301e2336&showforum=60Finally, these people are bullies, but the law is clear, you do not have to tell them who was driving, nor have any legal obligation to reply to them whatsoever. And unless you tell them who was driving they can't ake the matter further.