Do I need a DA for a freestanding storage unit in my car space?

I’d like to install a 2.4x 2m, over the bonnet storage unit in my car space. It would not be permanently fixed to the floor or walls and is low enough to ensure it doesn’t touch any gas or water pipes above. 

A neighbour who is worried about the unit disrupting her parking has suggested that a DA is required for this installation. One of her main points is that the legs of the storage unit may encroach on half of the car park lines. 

We have a by-law in place that allows the installation of such storage units within the car spaces in our apartment block. This has been active since 2015. 

Any thoughts or knowledge on this would be greatly appreciated.