Here is a link to a thread that has links to a number of distributors.
http://www.bimmer.info/forum/showthread.php?t=12913
What I have been told but don't know for sure is that the 535 doors have clips on them that hold the trim. In the description of one of these products, it appears to be stick-on however.
I think BigKriss put new trim in his car recently. Maybe he can shed some light on this.
And welcome to the forum. Where is NSW?