1. Don't drive like a tool = less chance of defect
2. Don't have a super-dooper-mega-whistle-hearitbeforeyouseethecar BOV = less chance of defect
3. Keep your car at a reasonable height = less chance of defect
4. Don't be a rice cooker with neons and stickers = less chance of defect
I have had a 33 with pretty major underbonnet works, loud as, but have not had that defected.
I now have a 32 with damn loud exhaust, but all else looks stock... (so far) no trouble.
As with anywhere, if you cause trouble with your car, expect to be bent over.
Welcome to Melb!!
PS I am going to Perth this arvo on business! Better be some good weather