WA DOT/POL is run by some very nanny thinking people, they have been on a campaign since the early 2000's to rid all cars older than 1990 from the road, and put a halt to all and any modifications(including factory option to model cars, ie V8 in 6cyl holden, turbo engine into n/a VL/jap car etc).
There was a big report commissioned into road safety and crash data ~4 years back which when viewed from their nanny head-in-arse position lead to current we-make-out-own-rules WA policies, and hoon laws etc, I have read several letters and been lectured too personally about crash safety of older cars and reasons why they don't want to allow HP in older cars, and there are some valid arguments against it, a little paranoid, but they are valid arguments, and denying they exist like a lot of pro modification people doesn't strengthen your argument.
Its also a pity at the same time engineering to improve performance and safety is flat out refused with no consideration because its too hard and no one wants to understand it.
I've been modifying cars since the 80's, and I knew from the start(probably from driving farm hacks on dirt and doing stupid shit since I was old enough to reach the pedals myself..been real lucky!), that common sense is a must have, a man's gotta know his and his cars limitations, modifications can't be a death trap and you keep your fuccking head down when your doing/driving something that's not quiet legal !
It gives the departments way too much fuel for their own nanny argument with all these big hp cars in magazines and on social media which, have plates on them, are shown driven on the road.... and then talked about in the interview being "great and nice to drive on the street" <- which most of the time total bs, a big stall full manual auto with solid drive line mounts, kirky seats etc etc sucks balls to drive for any distance.
TLDR: If you want to be a hoon and drive your race car on the street, time and place and Keep Your frOcking head down so you don't draw attention and ruin it for everyone.