I don't know much about the law change, but I presume if true, the fact they need to proove their out of pocket expense is still required in court, ie. They have to proove what your alleged breach of contract actualy cost them and they can't keep bumping the bill up if you don't pay on time.
As is not a fine, it's an invoice/civil case based in breach of contract.
They would surely still have to proove a contract was entered into, ie enter the carpark. I'm not clear how the registered keeper can be held responsible if they were not present to agree to the contract.it would be like getting a mobile phone contract in someone else's name...
A test case is badly needed to set a president.