Actually sidepipes are legal in Vic, or more accurately there are no ADR's or local state laws that prohibit them. To get an ICV with sidepipes registered I believe the requirements would fall into two areas;
1) the engineer would have to sign off on "general safety requirements" (I forget the actual ADR) e.g. engineer may determine that heat shields are needed.
2) pass the noise test
The ADR you may be thinking of regarding to exhaust pointing at the footpath, was deleted years ago.
With a 540ci engine, good luck with number 2) above
, and while we're at it good luck with the emissions test!