If it's not your factory BOV, take it off and put it back on after inspection. Be careful not to discuss any modifications you have done, in particular boost control, fuel computers, ECU's, etc. They will happily sit there listening to you tell them all about it acting very casual, and then they will whack an EPA notice on your car giving you 30 days to return the car to stock or have a full emissions test done, or they will instruct VicRoads to cancel or suspend your car's registration. EPA have quite alot of authority, and VicRoads will follow whatever the EPA tell them. They can be total bureaucratic pricks.