Using Car Space as storage area

Our 30year old block has individual car spaces within an open garage area secured by a button entry rolladoor.  This was not an original feature of the building but installed some 20 years ago to circumvent break-ins. Given the car spaces are on title, I understand residents can use this space for storage as well as (in some cases instead of) car parking.  Is there a way to limit the volume of items stored – for example, one space contains a trailer around and above which items are stored to the ceiling and to the line of adjoining residents' space.  It would seem to present a risk of damage to person and/or property.  Any advice on how to handle?