Its nice to hve a permit, but 85% of people who get a cam and exhaust, don't bother until the day they get a sticker. Drive sensible and keep the exhaust reasonably under the radar ie not stupid loud, then you should be fine cops look mainly at WHO'S DRIVING THE CAR, a 19 yo in a modified HSV/Holden then id seriously look at permits. If in the event you do get pulled up for a RBT or speeding ect, make sure you turn the car off straight away, and play the game. I wouldn't loose any sleep about not having a permit. How many car dealers in WA selling cars with SC and Cams ect and not permitted at all about 98%. There is abit of a loop hole, whereas performance shops do modifications with sending the customer on there merry way with in essence a illegally modified car, I personally think the customer should be made aware of the consequences of such upgrades ie cam mainly in the event of a licensing issue. A full exhaust system and Intake are easy to get permits as long as its under legal noise. The big DRAMAS can be aftermarket camshafts with lots of overlap nearly impossible to pass emmissions.. It becomes legal once its passed gas test, engineers report and finally a pits examination.