Monique,
Other posters make some good points, but I’d like to clarify (and elab0rate) on a couple based on recent experience.
1. Many folk use their car space to store household goods. Your best chance to get the items removed is if you can prove they are a fire hazard. If so, report the matter (with photographs) to the strata committee (do you have one?) and managing agent. I recall (in one scheme I am involved in) folk storing old chairs and tables in car spaces. It was a ghastly sight. The complainant (not me as it was nowhere near my side of the garage, so it did not interest me) got nowhere appealing to the selfish individual nor to the strata committee;
2. If non hazardous items are stored entirely within a car space, some will argue that you have no case (unless there are by laws relating to this);
3. Is there a by law prohibiting owners and tenants from
(a) using car spaces for anything other than parking motor vehicles?; and
(b) parking anywhere but their allocated car space?
If not, then such by laws would be a good addition to your scheme’s menu of by laws. They would be stronger than a by law merely prohibiting parking in the visitor’s car spaces; and
4. While a Notice to Comply (NTC) with a by law is often suggested, please note that according to NSW Fair Trading:
The strata committee, or owners corporation (if it has decided not to let the strata committee issue this Notice), must convene and hold a meeting to decide to issue this Notice or to issue notices for the type of breaches concerned in this Notice, and record its decision in the minutes. Alternatively, a managing agent who has been delegated the function may decide to issue this Notice.
Note: even if you have no committee and the agent was delegated all the powers, he will most likely dance to the tune of the person who championed his hire. Say that person still lives in your complex and has a view on the matter, it’s short odds that the agent will ape those views.
I have seen too often situations where the strata committee refuses point blank to consider issue such a notice, let alone issue a NTC especially when the offender is a committee member.
So at the very least you must (a) familiarise yourself with the by laws of your scheme; (b) write to the strata committee and managing agent listing your concern – or just the agent if there is no committee – pointing out if you believe that a by law or by laws are being breached, attach photographs and state what outcome you want; and (c) ask for your letter to be included in the agenda for the next meeting be it a strata committee or general meeting. That way, while the committee (if there is one) and agent may do sweet nothing, the evidence is clear: you brought the matter to their attention and they declined to act.
If the strata committee or managing agent DECLINE to list your letter on the agenda, then they are failing in their duties and that will require a different strategy on your part.