Ok, I'm going to get a custom exhaust system put on my 81ZXnz for like $350cdn. Stainless steel btw. ANyway, I was wondering why the **** the pipe goes from one side of the car to the other at the back just after the muffler. Is there ANY advantage to this at all? Also, what diameter pipe should I use? My guess is 2.5 inch. If anyone has any exhaust pointers or recommendations for me, I'd love to hear them! Thanks in advance.