We had the same problem a few weeks ago Hippy!!!!!!
We parked at Beuarepaires and got a dodgy looking pink photocopied parking ticket for $33, which said if we didn't say in 14 days it would go up to $55.
My b/f rang the council and the guy told him that legally there is no way they can find out who you are as they do not have the authority to do number plate searches, unlike the council. He advised him not to pay it.
My b/f then rang Parkfast and told them what the council had told him and Parkfast admitted that it was true and they could not find out who he is. He told them he would not pay the fine, so the guy told him to disregard it and he would rip it up!!