So, your neighbours have effectively annexed common property for their private use so they can extend the effective living area of their homes, without compensation to the Owners Corporation.
This is a land-grab by any other name and your Owners Corp should be asked exactly why they are allowing this to happen without any payment to the OC.
Maybe they don’t want to call it a parking area because that would involve a DA from the local council, but a parking area is exactly what it is. And while they are pleading innocence and trying to show that they are just being good neighbours, they are also deliberately playing fast and loose with the truth.
Is it a parking area? If it has feathers, waddles and quacks like a duck … it’s probably a duck. But it’s time to stop fighting aboput who parks where and say – OK, if you want to play it that way, there a re rules and processes that you have to follow.
Your motion at the AGM should be that the Owners Corporation seeks suitable compensation from the beneficiaries of their generosity as well as a by-law that passes ongoing responsibility for the parking area to the people who park on it so that they can have a games room.
Otherwise the OC should order the owners not to park there and pursue them with notices to comply if they do so. If they fail to do that, then you can (and probably should) pursue the committee through NCAT for failure to fulfil their responsibilities under the Act.