Simone is right, of course, the maximum fine for ignoring a valid notice to comply is $550. But somewhere in the back of my mind there was the much scarier $5.5K which, it turns out, is the maximum fine for failure to observe a CTTT order.
In short, if the rogue parkers ignore a valid Owners Corporation Notice To Comply they can be hit with a fine of up to $550. If they ignore a CTTT order to not park on common property, they face a fine of up to $5,500 for failure to observe the CTTT order.
Me, I'd go the slightly exaggerated but more tactical route of scaring them with huge amounts of money that may or may not be applicable. I mean, a couple of years ago an idiot journalist wrote that you could go to jail for drying your washing on your balcony. True if you ignored a notice to comply, then a CTTT order, then refused to pay the fine and then said you'd rather go to jail than pay it. Rubbish, of course, but it got the model by-laws changed.
Exaggeration or not, the intent is to get them to change their behaviour rather than go through the agonies and uncertainties of CTTT hearings.
Also, if the OC declines to get involved – “It's between two neighbours” is the usual excuse, you can go to Fair Trading as an individual and ask them to issue the NTC.