What about a 2008 commodore with darker than legal window tint? Or some 45yo doctor buys a new Senator and loves some 19" rims that are outside legal specs? These are illegal modifications too. I daresay there is a large percentage of the population that are driving around in a defectable car.
Then there are the ones who know nothing about cars, don't modify their car, (and hate people that do) yet they are driving around on 2 tyres worn down to the canvas, brakes metal to metal or shocks that may as well not be there....the list goes on.
We can't be singled out as people driving 'illegal or non-roadworthy' cars, as most of the cars I have worked on have had some form of defect or unroadworthy problem on them.
I even heard a rumour once that brand new cars such as falcons were leaving the factory with numerous defectable items. Don't know how true that is though!