Ok I can help with SA, if the paperwork says you need to present the vehicle to regency inspection station (which is 90% of defect cases), it will be a full check of every nut and bolt on that car, not just checking tyres.
Very very few people pass the first time as most 'normal' wear on mechanical components (bushes, suspension, brakes etc) will get knocked back. You basically need to get the car to showroom fresh condition to pass and remove any mods. Our inspection stations are government run with government inspectors and we don't get through as easily as the mechanic/workshop based roadworthy system of the eastern states.
By the sound of it you have a turbo on a car thats not meant to have a turbo, all that will have to come off and the car will essentially need to be stock for you to even have a chance of passing, the inspection takes around 1 hour so that shows the level of detail they go to.
If you have any worn components (even a little worn), any oil leaks etc you will need to get them fixed.
I've seen people failed in SA for small tears in seats, low fluid level in the windscreen washer bottle, window tint (even dealer supplied).