Stilt Parking Allotment

Our building had gone for redevelopment and hence when the OC was received and the occupation taken, we already had a co-op. society in existence. The builder had sold stilt parking to both old flat-owner and new purchasers. Almost 100% of the managing committee, composition of which remains the same over many years, comprises those who have bought stilt parking from the builder. So even if the act of buying stilt parking from the builder can be established as "illegal", the fact that the committee members are "owners" of such stilt parking, they can very well make permanent allotment of parking, ensuring that they do not lose their stilt parking, which they have done. Moreover those who own stilt parking also convey that space to tenants when they rent out their properties. So many society members park their cars in the open whereas tenants get stilt parking. Is this legal? Also if a member has 2 cars, does his second car parking get priority over the tenant's 1st car parking (whether open or stilt)?