Hi scotlandx – thanks for the comment 
– there is an EGM coming up in a few days and I’ve asked for a by-law for exclusive use of common property to be voted on – the by-law also includes a proviso that my parking encroachment causes no increased risk, obstruction, harm or interference to other lot users, and provides for payment of a market value rental if the body corporate deems this appropriate.
I hope that asking the body corporate to vote on a by-law will be less ambiguous than simply seeking written permission from them. Afterall, if i contravene my own by-law, i am now accountable to the CTTT.