Your strata manager seems a little sympathetic to the miscreants, who are obviously doing things for their convenience at the expense of other residents.
Depending upon what delegation she has, it may be necessary for the Executive Committee to meet and agree to a Notice to Comply with a By-law to be issued against Kellys.
This is the first step in taking the matter further to take action in the Tribunal.
The procedure is here: http://www.flatchat.com.au/by-laws-and-breaches-the-options/
I wonder whether it would possible to install a bollard or similar obstruction to physically prevent cars parking in those critical spots.