Rob, In the past I've had my car protested or a request for action or whatever they call it, by tech staff and it was physically kept in the tech building for two days to insure that I didn't try and change anything on it. The holes mentioned will allow a piece of wire to be run through the bolt heads and a seal put on the wire. So there would be no way to say change an illegal intake for a legal one without removing the sealed wire. In most cases this would also prevent the head from being changed. If you did have to change a sealed item you would simply notify tech and they would watch you make the repair and inspect the parts in question or ask you to bring the car to tech to work on it.