I think in brief that cars should not be parked on common property especially on access driveways where the car may impede entry and exit to the buildings garages.As a previous posting says once 1 car starts doing it others will follow with even visitors parking all over the place.
If a parked car gets hit by another this is not covered by strata insurance as the vechicle was in effect parked illegally on common property.Visitors cars must be parked in the designated area if your complex has a special area marked visitors only.No area than park on public road.
Of course there are no parking police patrolling the site so any problems refer them to the strata manager.