@KalebM did you mean bold tyres = sitting proud of the vehicle body or bald tyres = tread below legal limits
I think the later and blame it on autocorrect
I’d have thought the police would have explained the whole defect process to you when they issued the notice (trust you were listening). I’d also have thought that the defect notice should have included some statement that you can drive the car for a give period OR you can’t drive it at all and it must be trailered home and/or to a place of repair. I’d also have thought there must be some statement on the notice itself how the defect could be cleared.
But if the police were nice enough to let you drive away, and in your case it
seems they were nice enough since they chose not to go over the car in detail, then it’s usually enough to just fix the listed defect issue, get a roadworthy done and present the roadworthy to the rego authorities (where the take some money from you and clear the defect notice). Not all defects require the rego authority to inspect the vehicle.
The problem you may have could be that as the vehicle is not registered as a turbo, and it’s likely a no factory install with “bling”, even getting a roadworthy may prove to be a problem unless you have engineering docs for the mod. It’s the same problem if the rego authority require that they inspect the vehicle as they’ll go from bumper to bumper and notice the non standard turbo install. Either way you may be done. At least you weren’t done for driving a turbo as a P-plater (yet).
My suggestion is ring up your state rego authority and ask them what needs to be done, then chat to a mechanic who does roadworthy’s and see what will come of it? Maybe the mechanic that did the turbo install should be the mechanic you approach for your roadworthy?
Good luck with it, you may need it.