When you bought your lot, you acquired the living space, which comprises the space between your walls, and a designated parking space, the dimensions of which are onthestrata plan.
It’s not necessarily as cut and dried as you suggest. If the parking space is common property, he bought the right to be able to park his car on common property, and he could make a convincing argument that the space allocated is not fit for purpose.
He might discover, for instance, that the committee allocates the spaces and they have snaffled all the usable ones when the previous owner left.
However, if the parking space is part of his lot, that’s a whole different story and then it’s the hassle of buying or leasing more space from the owners corp.