I will jump to davids defence here he is correct in saying that you can get a cobra registered with the exhaust flowing down the side of the car and then back under and out the back i did it with a well know turbo charged cobra.
It passed rego the only conditions put on by the engineer was noise and heat sheilds where they ran down the side of the cobra .
They were in a sence not side pipe but just a different way to get it out the back . Helps a heap with ground clearance.
needless to say that for some strange reason the back half of the exhaust system rusted and fell off . It sounded so good i never replaced the back half
Regards oz