I have someunderbody lighting too on my magna, I've been stickered for it too which sucks.
Basically you are not allowed to see the tube AT ALL.
One time I got pulled up they let me off with a warning saying "hide it, sticky tape it, or paint it"
another time i got pulled up (stickered) they said tape or paint is not allowed, the tube has to be hidden.
they can also defect your car if your lights FLASH or >> CAN BE MADE TO FLASH << which is bs, because almost all of them can be made to flash, just tell them they cant be made to flash
There's a document on the DPI website about it which i printed off and keep in my car, i'll have a look for that shortly, have to start work now someone may have already posted it though