RS Gav. I used to live in Adelaide and upgrading your engine etc used to be a no no. Last time I visited my Brother-in-law we went to a big car show and lots of people I spoke to said they had been booked by the cops for having modified cars. I had an Aussie built V6 Capri and I imported lots of tuning parts for it from the UK. It had flared arches , lowered suspension, bigger wheels etc and looked and went well. I got stopped by the cops and they defected it and told me I had to put it back to standard!!! To say I was pissed off is an understatement!!
Sounds like WA is not as strict as South Australia.
Your car sounds like it will be a beast!!