P Plate modifications VS Insurance VS Police

[MWTB]

So as we all know, P platers aren't allowed ANY engine modifications by law.

Now, is this only a problem as far as the police and the VicRoads patrol are concerned, or will putting various engine mods on your ride also affect your insurance?

I'm 20 years old, so I'm a green P plater. Will putting extractors/cat back exhausts and such render my insurance void if I am involved in a crash?

I'm not too concerned about police noticing my modifications while I'm out and about, but I really am worried about what will happen if my car gets written off and they turn around and say 'no, legally you aren't allowed to have this, we're not going to honour your coverage'.